diff --git a/cmake/dotnet.cmake b/cmake/dotnet.cmake
index 12ead2117a8..e241e01c260 100644
--- a/cmake/dotnet.cmake
+++ b/cmake/dotnet.cmake
@@ -20,6 +20,7 @@ if(NOT TARGET ${PROJECT_NAMESPACE}::ortools)
 endif()
 
 # Will need swig
+set(SWIG_SOURCE_FILE_EXTENSIONS ".i" ".swig")
 set(CMAKE_SWIG_FLAGS)
 find_package(SWIG REQUIRED)
 include(UseSWIG)
diff --git a/cmake/java.cmake b/cmake/java.cmake
index ae7f023c9d4..bd73e09dd2f 100644
--- a/cmake/java.cmake
+++ b/cmake/java.cmake
@@ -20,6 +20,7 @@ if(NOT TARGET ${PROJECT_NAMESPACE}::ortools)
 endif()
 
 # Will need swig
+set(SWIG_SOURCE_FILE_EXTENSIONS ".i" ".swig")
 set(CMAKE_SWIG_FLAGS)
 find_package(SWIG REQUIRED)
 include(UseSWIG)
diff --git a/cmake/python.cmake b/cmake/python.cmake
index 6d4fbde01e3..d7173f9abe2 100644
--- a/cmake/python.cmake
+++ b/cmake/python.cmake
@@ -23,6 +23,7 @@ if(NOT TARGET ${PROJECT_NAMESPACE}::ortools)
 endif()
 
 # Will need swig
+set(SWIG_SOURCE_FILE_EXTENSIONS ".i" ".swig")
 set(CMAKE_SWIG_FLAGS)
 find_package(SWIG REQUIRED)
 include(UseSWIG)
diff --git a/ortools/algorithms/java/BUILD.bazel b/ortools/algorithms/java/BUILD.bazel
index dd3cb9da808..5b84c09b2f7 100644
--- a/ortools/algorithms/java/BUILD.bazel
+++ b/ortools/algorithms/java/BUILD.bazel
@@ -17,7 +17,7 @@ load("//bazel:swig_java.bzl", "ortools_java_wrap_cc")
 
 ortools_java_wrap_cc(
     name = "knapsacksolver",
-    src = "knapsack_solver.i",
+    src = "knapsack_solver.swig",
     module = "operations_research_algorithms",
     package = "com.google.ortools.algorithms",
     swig_includes = [
diff --git a/ortools/algorithms/java/CMakeLists.txt b/ortools/algorithms/java/CMakeLists.txt
index cfae6f41617..82c9e266919 100644
--- a/ortools/algorithms/java/CMakeLists.txt
+++ b/ortools/algorithms/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE knapsack_solver.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE knapsack_solver.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE knapsack_solver.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE knapsack_solver.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE knapsack_solver.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE knapsack_solver.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE knapsack_solver.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE knapsack_solver.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.algorithms)
 swig_add_library(jnialgorithms
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/algorithms
-  SOURCES knapsack_solver.i)
+  SOURCES knapsack_solver.swig)
 
 target_include_directories(jnialgorithms PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnialgorithms PROPERTIES
diff --git a/ortools/algorithms/java/knapsack_solver.i b/ortools/algorithms/java/knapsack_solver.swig
similarity index 98%
rename from ortools/algorithms/java/knapsack_solver.i
rename to ortools/algorithms/java/knapsack_solver.swig
index 429098139e3..17b4d45c423 100644
--- a/ortools/algorithms/java/knapsack_solver.i
+++ b/ortools/algorithms/java/knapsack_solver.swig
@@ -21,7 +21,7 @@
 %include "enums.swg"
 
 %include "ortools/base/base.i"
-%import "ortools/util/java/vector.i"
+%import "ortools/util/java/vector.swig"
 
 %{
 #include "ortools/algorithms/knapsack_solver.h"
diff --git a/ortools/base/python-swig.h b/ortools/base/python-swig.h
index 8c7003691a9..38dc43b8f56 100644
--- a/ortools/base/python-swig.h
+++ b/ortools/base/python-swig.h
@@ -13,7 +13,7 @@
 
 // Static part of SWIG-generated C++ wrapper for Python (_module_name.cc).
 //
-// This file should only be included in base.i inside Python-specific part:
+// This file should only be included in base.swig inside Python-specific part:
 //   #ifdef SWIGPYTHON
 //   %{
 //   #include "ortools/base/swig/python-swig.cc"
diff --git a/ortools/constraint_solver/java/CMakeLists.txt b/ortools/constraint_solver/java/CMakeLists.txt
index e1116674378..61e0ae1957d 100644
--- a/ortools/constraint_solver/java/CMakeLists.txt
+++ b/ortools/constraint_solver/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE constraint_solver.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE constraint_solver.i PROPERTY SWIG_MODULE_NAME Globals)
-set_property(SOURCE constraint_solver.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE constraint_solver.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE constraint_solver.swig PROPERTY SWIG_MODULE_NAME Globals)
+set_property(SOURCE constraint_solver.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE constraint_solver.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE constraint_solver.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.constraintsolver)
 swig_add_library(jniconstraint_solver
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/constraintsolver
-  SOURCES constraint_solver.i)
+  SOURCES constraint_solver.swig)
 
 target_include_directories(jniconstraint_solver PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jniconstraint_solver PROPERTIES
diff --git a/ortools/constraint_solver/java/constraint_solver.i b/ortools/constraint_solver/java/constraint_solver.swig
similarity index 99%
rename from ortools/constraint_solver/java/constraint_solver.i
rename to ortools/constraint_solver/java/constraint_solver.swig
index 88f8540460d..f27f5415ff6 100644
--- a/ortools/constraint_solver/java/constraint_solver.i
+++ b/ortools/constraint_solver/java/constraint_solver.swig
@@ -20,9 +20,9 @@
 %include "exception.i"
 
 %include "ortools/base/base.i"
-%include "ortools/util/java/absl_string_view.i"
-%include "ortools/util/java/tuple_set.i"
-%include "ortools/util/java/vector.i"
+%include "ortools/util/java/absl_string_view.swig"
+%include "ortools/util/java/tuple_set.swig"
+%include "ortools/util/java/vector.swig"
 %include "ortools/util/java/proto.i"
 
 // Make the SWIG-generated constructor public.
@@ -82,7 +82,7 @@ class GlobalRefGuard {
 %}
 
 // ############ BEGIN DUPLICATED CODE BLOCK ############
-// IMPORTANT: keep this code block in sync with the .i
+// IMPORTANT: keep this code block in sync with the .swig
 // files in ../python and ../csharp.
 
 // Protect from failure.
diff --git a/ortools/constraint_solver/python/CMakeLists.txt b/ortools/constraint_solver/python/CMakeLists.txt
index 8fe4444aa78..f40645ab1b1 100644
--- a/ortools/constraint_solver/python/CMakeLists.txt
+++ b/ortools/constraint_solver/python/CMakeLists.txt
@@ -32,16 +32,16 @@ target_link_libraries(constraint_solver_pybind11 PRIVATE
 add_library(${PROJECT_NAMESPACE}::constraint_solver_pybind11 ALIAS constraint_solver_pybind11)
 
 # legacy pywrapcp
-set_property(SOURCE constraint_solver.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE constraint_solver.i PROPERTY SWIG_MODULE_NAME pywrapcp)
-set_property(SOURCE constraint_solver.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE constraint_solver.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE constraint_solver.swig PROPERTY SWIG_MODULE_NAME pywrapcp)
+set_property(SOURCE constraint_solver.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE constraint_solver.i PROPERTY COMPILE_OPTIONS -nofastunpack)
+set_property(SOURCE constraint_solver.swig PROPERTY COMPILE_OPTIONS -nofastunpack)
 swig_add_library(pywrapcp
   TYPE MODULE
   LANGUAGE python
   OUTPUT_DIR ${PYTHON_PROJECT_DIR}/constraint_solver
-  SOURCES constraint_solver.i)
+  SOURCES constraint_solver.swig)
 
 target_include_directories(pywrapcp PRIVATE ${Python3_INCLUDE_DIRS})
 set_property(TARGET pywrapcp PROPERTY SWIG_USE_TARGET_INCLUDE_DIRECTORIES ON)
diff --git a/ortools/constraint_solver/python/constraint_solver.i b/ortools/constraint_solver/python/constraint_solver.swig
similarity index 99%
rename from ortools/constraint_solver/python/constraint_solver.i
rename to ortools/constraint_solver/python/constraint_solver.swig
index 498e4af1466..c4e8c5bb04e 100644
--- a/ortools/constraint_solver/python/constraint_solver.i
+++ b/ortools/constraint_solver/python/constraint_solver.swig
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i file exposes the code declared in ../constraint_solver.h and
+// This .swig file exposes the code declared in ../constraint_solver.h and
 // ../constraint_solveri.h.
 //
 // It is particularly complex for a swig file, mostly because it contains a
@@ -35,12 +35,12 @@
 %include "ortools/util/python/proto.i"
 
 // PY_CONVERT_HELPER_* macros.
-%include "ortools/constraint_solver/python/constraint_solver_helpers.i"
+%include "ortools/constraint_solver/python/constraint_solver_helpers.swig"
 
-%include "ortools/util/python/functions.i"
-%include "ortools/util/python/vector.i"
+%include "ortools/util/python/functions.swig"
+%include "ortools/util/python/vector.swig"
 
-%include "ortools/constraint_solver/python/pywrapcp_util.i"
+%include "ortools/constraint_solver/python/pywrapcp_util.swig"
 
 // We *do* need to use SWIGTYPE_... type names directly, because the
 // (recommended replacement) $descriptor macro fails, as of 2019-07, with
@@ -103,7 +103,7 @@ struct FailureProtect {
 
 // ============= Type conversions ==============
 
-// See ./constraint_solver_helpers.i
+// See ./constraint_solver_helpers.swig
 PY_CONVERT_HELPER_PTR(Constraint);
 PY_CONVERT_HELPER_PTR(Decision);
 PY_CONVERT_HELPER_PTR(DecisionBuilder);
@@ -131,7 +131,7 @@ PY_CONVERT(LocalSearchFilter);
 PY_CONVERT(LocalSearchFilterManager);
 
 // Support passing std::function<void(Solver*)> as argument.
-// See ../utils/python/functions.i, from which this was copied and adapted.
+// See ../utils/python/functions.swig, from which this was copied and adapted.
 
 %{
 static void PyFunctionSolverToVoid(PyObject* pyfunc,
@@ -647,10 +647,10 @@ PY_STRINGIFY_DEBUGSTRING(Decision);
 }
 
 // ############ BEGIN DUPLICATED CODE BLOCK ############
-// IMPORTANT: keep this code block in sync with the .i
+// IMPORTANT: keep this code block in sync with the .swig
 // files in ../java and ../csharp.
 // TODO(user): extract this duplicated code into a common, multi-language
-// .i file with SWIG_exception.
+// .swig file with SWIG_exception.
 
 // Protect from failure.
 // TODO(user): document this further.
@@ -1911,7 +1911,7 @@ RENAME_ASSIGNMENT_CONTAINER(
 
 }  // namespace operations_research
 
-// ================= constraint_solver.i API =====================
+// ================= constraint_solver.swig API =====================
 
 namespace operations_research {
 
diff --git a/ortools/constraint_solver/python/constraint_solver_doc.h b/ortools/constraint_solver/python/constraint_solver_doc.h
index c8dff6346f2..73d207c446d 100644
--- a/ortools/constraint_solver/python/constraint_solver_doc.h
+++ b/ortools/constraint_solver/python/constraint_solver_doc.h
@@ -5715,7 +5715,7 @@ static const char* __doc_operations_research_Solver_SetUseFastLocalSearch =
     R"doc(enabled for metaheuristics. Disables/enables fast local search.)doc";
 
 static const char* __doc_operations_research_Solver_ShouldFail =
-    R"doc(See http://cs/file:constraint_solver.i%20ShouldFail.)doc";
+    R"doc(See http://cs/file:constraint_solver.swig%20ShouldFail.)doc";
 
 static const char* __doc_operations_research_Solver_Solve =
     R"doc(@{ Solves the problem using the given DecisionBuilder and returns true
diff --git a/ortools/constraint_solver/python/constraint_solver_helpers.i b/ortools/constraint_solver/python/constraint_solver_helpers.swig
similarity index 97%
rename from ortools/constraint_solver/python/constraint_solver_helpers.i
rename to ortools/constraint_solver/python/constraint_solver_helpers.swig
index 22f0e21189c..576a912ec3b 100644
--- a/ortools/constraint_solver/python/constraint_solver_helpers.i
+++ b/ortools/constraint_solver/python/constraint_solver_helpers.swig
@@ -32,7 +32,7 @@ PyObject* PyObjFrom<int64_t>(const int64_t& c) {
 
 // Conversion of IntExpr* and IntVar* are a bit special because of the two
 // possible casts from IntExpr and Constraint. We define them here because
-// they are used by both constraint_solver.i and routing.i, but need to
+// they are used by both constraint_solver.swig and routing.swig, but need to
 // be defined at a point where IntVar/IntExpr are known.
 %define PY_CONVERT_HELPER_INTEXPR_AND_INTVAR()
 %{
diff --git a/ortools/constraint_solver/python/pywrapcp_util.i b/ortools/constraint_solver/python/pywrapcp_util.swig
similarity index 92%
rename from ortools/constraint_solver/python/pywrapcp_util.i
rename to ortools/constraint_solver/python/pywrapcp_util.swig
index 9ecb76dd590..dedd8006b98 100644
--- a/ortools/constraint_solver/python/pywrapcp_util.i
+++ b/ortools/constraint_solver/python/pywrapcp_util.swig
@@ -11,11 +11,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i file cannot be used in isolation!
-// It represents some of the inlined C++ content of ./constraint_solver.i,
+// This .swig file cannot be used in isolation!
+// It represents some of the inlined C++ content of ./constraint_solver.swig,
 // and was split out because it's a large enough chunk of C++ code.
 //
-// It can only be interpreted in the context of ./constraint_solver.i, where
+// It can only be interpreted in the context of ./constraint_solver.swig, where
 // it is included.
 %{
 #include <string>
diff --git a/ortools/graph/csharp/graph.i b/ortools/graph/csharp/graph.i
index d51b07c3b5e..791c3225136 100644
--- a/ortools/graph/csharp/graph.i
+++ b/ortools/graph/csharp/graph.i
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i file is only used in the open-source export to OR-Tools.
+// This .swig file is only used in the open-source export to OR-Tools.
 //
 // It exposes some of the C++ classes in ../, namely :
 // - SimpleMaxFlow, from ../max_flow.h
diff --git a/ortools/graph/java/BUILD.bazel b/ortools/graph/java/BUILD.bazel
index 25e7ba18ae3..4818a860925 100644
--- a/ortools/graph/java/BUILD.bazel
+++ b/ortools/graph/java/BUILD.bazel
@@ -19,7 +19,7 @@ load("//bazel:swig_java.bzl", "ortools_java_wrap_cc")
 
 ortools_java_wrap_cc(
     name = "graph",
-    src = "graph.i",
+    src = "graph.swig",
     module = "graph",
     package = "com.google.ortools.graph",
     swig_includes = [
diff --git a/ortools/graph/java/CMakeLists.txt b/ortools/graph/java/CMakeLists.txt
index 6054afd20d2..0dfe0486365 100644
--- a/ortools/graph/java/CMakeLists.txt
+++ b/ortools/graph/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE graph.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE graph.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE graph.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE graph.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE graph.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE graph.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE graph.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE graph.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.graph)
 swig_add_library(jnigraph
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/graph
-  SOURCES graph.i)
+  SOURCES graph.swig)
 
 target_include_directories(jnigraph PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnigraph PROPERTIES
diff --git a/ortools/graph/java/graph.i b/ortools/graph/java/graph.swig
similarity index 99%
rename from ortools/graph/java/graph.i
rename to ortools/graph/java/graph.swig
index db096aa6448..222e968fbed 100644
--- a/ortools/graph/java/graph.i
+++ b/ortools/graph/java/graph.swig
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i files exposes some of the C++ classes in ../, namely :
+// This .swig files exposes some of the C++ classes in ../, namely :
 // - MaxFlow, from SimpleMaxFlow in ../max_flow.h
 // - MinCostFlow, from SimpleMinCostFlow in ../min_cost_flow.h
 // - LinearSumAssignment, from SimpleLinearSumAssignment in ../assignment.h
diff --git a/ortools/init/java/init.i b/ortools/init/java/init.i
index 5f16276062a..d042d3afab2 100644
--- a/ortools/init/java/init.i
+++ b/ortools/init/java/init.i
@@ -15,7 +15,7 @@
 
 %include "std_string.i"
 
-%include "ortools/util/java/absl_string_view.i"
+%include "ortools/util/java/absl_string_view.swig"
 
 %{
 #include "ortools/init/init.h"
diff --git a/ortools/init/python/init_test.py b/ortools/init/python/init_test.py
index 18708e4ffae..9988e6b6b72 100755
--- a/ortools/init/python/init_test.py
+++ b/ortools/init/python/init_test.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Simple unit tests for python/init.i. Not exhaustive."""
+"""Simple unit tests for python/init.swig. Not exhaustive."""
 
 from absl.testing import absltest
 from ortools.init.python import init
diff --git a/ortools/linear_solver/java/BUILD.bazel b/ortools/linear_solver/java/BUILD.bazel
index cad9cc2a3ad..0cf3c002268 100644
--- a/ortools/linear_solver/java/BUILD.bazel
+++ b/ortools/linear_solver/java/BUILD.bazel
@@ -19,7 +19,7 @@ load("//bazel:swig_java.bzl", "ortools_java_wrap_cc")
 
 ortools_java_wrap_cc(
     name = "modelbuilder",
-    src = "modelbuilder.i",
+    src = "modelbuilder.swig",
     module = "modelbuilder",
     package = "com.google.ortools.modelbuilder",
     swig_includes = [
diff --git a/ortools/linear_solver/java/CMakeLists.txt b/ortools/linear_solver/java/CMakeLists.txt
index 9b10ca3b966..a09642c0d72 100644
--- a/ortools/linear_solver/java/CMakeLists.txt
+++ b/ortools/linear_solver/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE linear_solver.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE linear_solver.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE linear_solver.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE linear_solver.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE linear_solver.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE linear_solver.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE linear_solver.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE linear_solver.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.linearsolver)
 swig_add_library(jnilinear_solver
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/linearsolver
-  SOURCES linear_solver.i)
+  SOURCES linear_solver.swig)
 
 target_include_directories(jnilinear_solver PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnilinear_solver PROPERTIES
@@ -29,17 +29,17 @@ set_target_properties(jnilinear_solver PROPERTIES
   POSITION_INDEPENDENT_CODE ON)
 target_link_libraries(jnilinear_solver PRIVATE ortools::ortools)
 
-set_property(SOURCE modelbuilder.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE modelbuilder.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE modelbuilder.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE modelbuilder.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE modelbuilder.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE modelbuilder.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE modelbuilder.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE modelbuilder.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.modelbuilder)
 swig_add_library(jnimodelbuilder
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/modelbuilder
-  SOURCES modelbuilder.i)
+  SOURCES modelbuilder.swig)
 
 target_include_directories(jnimodelbuilder PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnimodelbuilder PROPERTIES
diff --git a/ortools/linear_solver/java/linear_solver.i b/ortools/linear_solver/java/linear_solver.swig
similarity index 99%
rename from ortools/linear_solver/java/linear_solver.i
rename to ortools/linear_solver/java/linear_solver.swig
index 5c4b24c4158..958239412cb 100644
--- a/ortools/linear_solver/java/linear_solver.i
+++ b/ortools/linear_solver/java/linear_solver.swig
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i file exposes the linear programming and integer programming
+// This .swig file exposes the linear programming and integer programming
 // solver. See the C++/Python codelab:  (there isn't
 // a java codelab yet, as of July 2014)
 //
@@ -33,7 +33,7 @@
 
 // We prefer our in-house vector wrapper to std_vector.i, because it
 // converts to and from native java arrays.
-%import "ortools/util/java/vector.i"
+%import "ortools/util/java/vector.swig"
 
 %include "ortools/util/java/proto.i"
 
diff --git a/ortools/linear_solver/java/modelbuilder.i b/ortools/linear_solver/java/modelbuilder.swig
similarity index 99%
rename from ortools/linear_solver/java/modelbuilder.i
rename to ortools/linear_solver/java/modelbuilder.swig
index f8c526c1b05..441039dba60 100644
--- a/ortools/linear_solver/java/modelbuilder.i
+++ b/ortools/linear_solver/java/modelbuilder.swig
@@ -15,7 +15,7 @@
 
 %include "ortools/base/base.i"
 %include "enums.swg"
-%include "ortools/util/java/vector.i"
+%include "ortools/util/java/vector.swig"
 
 %{
 #include "ortools/linear_solver/wrappers/model_builder_helper.h"
@@ -27,7 +27,7 @@
 // The only difference is that the argument is not a basic type, and needs
 // processing to be passed to the std::function.
 //
-// TODO(user): cleanup java/functions.i and move the code there.
+// TODO(user): cleanup java/functions.swig and move the code there.
 %{
 #include <memory> // std::make_shared<GlobalRefGuard>
 
diff --git a/ortools/linear_solver/python/CMakeLists.txt b/ortools/linear_solver/python/CMakeLists.txt
index b7f0b586e4b..9a7b45984d5 100644
--- a/ortools/linear_solver/python/CMakeLists.txt
+++ b/ortools/linear_solver/python/CMakeLists.txt
@@ -11,15 +11,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE linear_solver.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE linear_solver.i PROPERTY SWIG_MODULE_NAME pywraplp)
-set_property(SOURCE linear_solver.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE linear_solver.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE linear_solver.swig PROPERTY SWIG_MODULE_NAME pywraplp)
+set_property(SOURCE linear_solver.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
 swig_add_library(pywraplp
   TYPE MODULE
   LANGUAGE python
   OUTPUT_DIR ${PYTHON_PROJECT_DIR}/linear_solver
-  SOURCES linear_solver.i)
+  SOURCES linear_solver.swig)
 
 target_include_directories(pywraplp PRIVATE ${Python3_INCLUDE_DIRS})
 set_property(TARGET pywraplp PROPERTY SWIG_USE_TARGET_INCLUDE_DIRECTORIES ON)
diff --git a/ortools/linear_solver/python/linear_solver.i b/ortools/linear_solver/python/linear_solver.swig
similarity index 99%
rename from ortools/linear_solver/python/linear_solver.i
rename to ortools/linear_solver/python/linear_solver.swig
index 2309ea3e4c1..028b3dbd96a 100644
--- a/ortools/linear_solver/python/linear_solver.i
+++ b/ortools/linear_solver/python/linear_solver.swig
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// This .i file exposes the linear programming and integer programming
+// This .swig file exposes the linear programming and integer programming
 // solver. See the C++/Python codelab: .
 //
 // The python API is enriched by custom code defined here, making it
@@ -35,7 +35,7 @@
 
 %include "ortools/util/python/proto.i"
 
-%import "ortools/util/python/vector.i"
+%import "ortools/util/python/vector.swig"
 
 // We need to forward-declare the proto here, so that the PROTO_* macros
 // involving them work correctly. The order matters very much: this declaration
diff --git a/ortools/linear_solver/python/linear_solver_natural_api.py b/ortools/linear_solver/python/linear_solver_natural_api.py
index 45e92652897..42a56a8697d 100644
--- a/ortools/linear_solver/python/linear_solver_natural_api.py
+++ b/ortools/linear_solver/python/linear_solver_natural_api.py
@@ -13,7 +13,7 @@
 
 """Patch to the python wrapper of ../linear_solver.h providing an algebraic API.
 
-This is directly imported, and use exclusively in ./linear_solver.i. See that
+This is directly imported, and use exclusively in ./linear_solver.swig. See that
 file.
 For examples leveraging the code defined here, see ./pywraplp_test.py and
 ../../../python/linear_programming.py.
diff --git a/ortools/linear_solver/python/pywraplp_test.py b/ortools/linear_solver/python/pywraplp_test.py
index 1f98234375a..ff35260334a 100644
--- a/ortools/linear_solver/python/pywraplp_test.py
+++ b/ortools/linear_solver/python/pywraplp_test.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Simple unit tests for python/linear_solver.i. Not exhaustive."""
+"""Simple unit tests for python/linear_solver.swig. Not exhaustive."""
 
 import unittest
 from ortools.linear_solver import linear_solver_pb2
diff --git a/ortools/routing/java/CMakeLists.txt b/ortools/routing/java/CMakeLists.txt
index 90aaca3e430..1d0b7e8dacc 100644
--- a/ortools/routing/java/CMakeLists.txt
+++ b/ortools/routing/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE routing.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE routing.i PROPERTY SWIG_MODULE_NAME Globals)
-set_property(SOURCE routing.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE routing.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE routing.swig PROPERTY SWIG_MODULE_NAME Globals)
+set_property(SOURCE routing.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE routing.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE routing.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.routing)
 swig_add_library(jnirouting
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/routing
-  SOURCES routing.i)
+  SOURCES routing.swig)
 
 target_include_directories(jnirouting PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnirouting PROPERTIES
diff --git a/ortools/routing/java/index_manager.i b/ortools/routing/java/index_manager.swig
similarity index 97%
rename from ortools/routing/java/index_manager.i
rename to ortools/routing/java/index_manager.swig
index 4e1670c0c73..f598513b304 100644
--- a/ortools/routing/java/index_manager.i
+++ b/ortools/routing/java/index_manager.swig
@@ -14,7 +14,7 @@
 // Wrapper for RoutingIndexManager.
 
 %include "ortools/base/base.i"
-%include "ortools/routing/java/types.i"
+%include "ortools/routing/java/types.swig"
 
 %{
 #include "ortools/routing/index_manager.h"
diff --git a/ortools/routing/java/routing.i b/ortools/routing/java/routing.swig
similarity index 99%
rename from ortools/routing/java/routing.i
rename to ortools/routing/java/routing.swig
index fcb6f6c2a3c..abc131dd948 100644
--- a/ortools/routing/java/routing.i
+++ b/ortools/routing/java/routing.swig
@@ -19,12 +19,12 @@
 %template(IntBoolPair) std::pair<int, bool>;
 
 %include "ortools/base/base.i"
-%include "ortools/util/java/vector.i"
+%include "ortools/util/java/vector.swig"
 %include "ortools/util/java/proto.i"
-%import "ortools/constraint_solver/java/constraint_solver.i"
-%import "ortools/util/java/sorted_interval_list.i" // Domain
+%import "ortools/constraint_solver/java/constraint_solver.swig"
+%import "ortools/util/java/sorted_interval_list.swig" // Domain
 
-%include "ortools/routing/java/index_manager.i"
+%include "ortools/routing/java/index_manager.swig"
 
 // We need to forward-declare the proto here, so that PROTO_INPUT involving it
 // works correctly. The order matters very much: this declaration needs to be
diff --git a/ortools/routing/java/types.i b/ortools/routing/java/types.swig
similarity index 98%
rename from ortools/routing/java/types.i
rename to ortools/routing/java/types.swig
index 45e27fbdfae..f9f6d0e3d35 100644
--- a/ortools/routing/java/types.i
+++ b/ortools/routing/java/types.swig
@@ -18,7 +18,7 @@
 // This file is to be %included when wrapped objects need to use these typemaps.
 
 %include "ortools/base/base.i"
-%import "ortools/util/java/vector.i"
+%import "ortools/util/java/vector.swig"
 
 %{
 #include "ortools/routing/types.h"
diff --git a/ortools/routing/python/CMakeLists.txt b/ortools/routing/python/CMakeLists.txt
index 9fe346f31bf..2c7e9e9dbb2 100644
--- a/ortools/routing/python/CMakeLists.txt
+++ b/ortools/routing/python/CMakeLists.txt
@@ -33,16 +33,16 @@ target_link_libraries(routing_pybind11 PRIVATE
 add_library(${PROJECT_NAMESPACE}::routing_pybind11 ALIAS routing_pybind11)
 
 # legacy pywraprouting
-set_property(SOURCE routing.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE routing.i PROPERTY SWIG_MODULE_NAME pywraprouting)
-set_property(SOURCE routing.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE routing.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE routing.swig PROPERTY SWIG_MODULE_NAME pywraprouting)
+set_property(SOURCE routing.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE routing.i PROPERTY COMPILE_OPTIONS -nofastunpack)
+set_property(SOURCE routing.swig PROPERTY COMPILE_OPTIONS -nofastunpack)
 swig_add_library(pywraprouting
   TYPE MODULE
   LANGUAGE python
   OUTPUT_DIR ${PYTHON_PROJECT_DIR}/routing
-  SOURCES routing.i)
+  SOURCES routing.swig)
 
 target_include_directories(pywraprouting PRIVATE ${Python3_INCLUDE_DIRS})
 set_property(TARGET pywraprouting PROPERTY SWIG_USE_TARGET_INCLUDE_DIRECTORIES ON)
diff --git a/ortools/routing/python/index_manager.i b/ortools/routing/python/index_manager.swig
similarity index 95%
rename from ortools/routing/python/index_manager.i
rename to ortools/routing/python/index_manager.swig
index 02dc547d8bf..27b1114f0f4 100644
--- a/ortools/routing/python/index_manager.i
+++ b/ortools/routing/python/index_manager.swig
@@ -14,8 +14,8 @@
 // Wrapper for RoutingIndexManager.
 
 %include "ortools/base/base.i"
-%include "ortools/routing/python/types.i"
-%import "ortools/util/python/vector.i"
+%include "ortools/routing/python/types.swig"
+%import "ortools/util/python/vector.swig"
 
 %{
 #include "ortools/routing/index_manager.h"
diff --git a/ortools/routing/python/routing.i b/ortools/routing/python/routing.swig
similarity index 93%
rename from ortools/routing/python/routing.i
rename to ortools/routing/python/routing.swig
index 4b49f36ab9f..417050ed1c3 100644
--- a/ortools/routing/python/routing.i
+++ b/ortools/routing/python/routing.swig
@@ -18,19 +18,19 @@
 %include "ortools/util/python/proto.i"
 
 // PY_CONVERT_HELPER_* macros.
-%include "ortools/constraint_solver/python/constraint_solver_helpers.i"
+%include "ortools/constraint_solver/python/constraint_solver_helpers.swig"
 
-%include "ortools/util/python/functions.i"
-%include "ortools/util/python/pair.i"
-%include "ortools/util/python/vector.i"
+%include "ortools/util/python/functions.swig"
+%include "ortools/util/python/pair.swig"
+%include "ortools/util/python/vector.swig"
 
 // While the module name will be overridden by the one specified on the cmd line,
 // without this, derived classes (e.g. TypeRequirementChecker) will import base
 // class from the module specified in the following %import.
 %module pywraprouting
-%import(module="ortools.constraint_solver.pywrapcp") "ortools/constraint_solver/python/constraint_solver.i"
-%include "ortools/routing/python/types.i"
-%include "ortools/routing/python/index_manager.i"
+%import(module="ortools.constraint_solver.pywrapcp") "ortools/constraint_solver/python/constraint_solver.swig"
+%include "ortools/routing/python/types.swig"
+%include "ortools/routing/python/index_manager.swig"
 
 // We need to forward-declare the proto here, so that PROTO_INPUT involving it
 // works correctly. The order matters very much: this declaration needs to be
@@ -69,7 +69,7 @@ DEFINE_INDEX_TYPE_TYPEDEF(
 
 // ============= Type conversions ==============
 
-// See ./constraint_solver_helpers.i.
+// See ./constraint_solver_helpers.swig.
 PY_CONVERT_HELPER_INTEXPR_AND_INTVAR();
 PY_CONVERT_HELPER_PTR(IntervalVar);
 PY_CONVERT_HELPER_PTR(LocalSearchFilter);
diff --git a/ortools/routing/python/types.i b/ortools/routing/python/types.swig
similarity index 98%
rename from ortools/routing/python/types.i
rename to ortools/routing/python/types.swig
index c7949de427c..09e0d4b617a 100644
--- a/ortools/routing/python/types.i
+++ b/ortools/routing/python/types.swig
@@ -18,7 +18,7 @@
 // This file is to be %included when wrapped objects need to use these typemaps.
 
 %include "ortools/base/base.i"
-%import "ortools/util/python/vector.i"
+%import "ortools/util/python/vector.swig"
 
 %{
 #include "ortools/routing/types.h"
diff --git a/ortools/sat/java/BUILD.bazel b/ortools/sat/java/BUILD.bazel
index dc1589eb1ef..76bc1a8521b 100644
--- a/ortools/sat/java/BUILD.bazel
+++ b/ortools/sat/java/BUILD.bazel
@@ -19,7 +19,7 @@ load("//bazel:swig_java.bzl", "ortools_java_wrap_cc")
 
 ortools_java_wrap_cc(
     name = "sat",
-    src = "sat.i",
+    src = "sat.swig",
     java_deps = [
         "//ortools/sat:cp_model_java_proto",
         "//ortools/sat:sat_parameters_java_proto",
diff --git a/ortools/sat/java/CMakeLists.txt b/ortools/sat/java/CMakeLists.txt
index ea6aeec7bfb..6f7243292b6 100644
--- a/ortools/sat/java/CMakeLists.txt
+++ b/ortools/sat/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE sat.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE sat.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE sat.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE sat.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE sat.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE sat.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE sat.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE sat.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.sat)
 swig_add_library(jnisat
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/sat
-  SOURCES sat.i)
+  SOURCES sat.swig)
 
 target_include_directories(jnisat PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jnisat PROPERTIES
diff --git a/ortools/sat/java/sat.i b/ortools/sat/java/sat.swig
similarity index 98%
rename from ortools/sat/java/sat.i
rename to ortools/sat/java/sat.swig
index af1b325e2bc..f2def937a9b 100644
--- a/ortools/sat/java/sat.i
+++ b/ortools/sat/java/sat.swig
@@ -17,7 +17,7 @@
 
 %include "ortools/util/java/proto.i"
 
-%import "ortools/util/java/sorted_interval_list.i"
+%import "ortools/util/java/sorted_interval_list.swig"
 
 %{
 #include "ortools/sat/cp_model.pb.h"
@@ -76,7 +76,7 @@ PROTO2_RETURN(operations_research::sat::CpSolverResponse,
 // The only difference is that the argument is not a basic type, and needs
 // processing to be passed to the std::function.
 //
-// TODO(user): cleanup java/functions.i and move the code there.
+// TODO(user): cleanup java/functions.swig and move the code there.
 %{
 #include <memory> // std::make_shared<GlobalRefGuard>
 %}
diff --git a/ortools/util/functions_swig_helpers.h b/ortools/util/functions_swig_helpers.h
index a3451091b62..41423970eaf 100644
--- a/ortools/util/functions_swig_helpers.h
+++ b/ortools/util/functions_swig_helpers.h
@@ -15,7 +15,7 @@
 #define OR_TOOLS_UTIL_FUNCTIONS_SWIG_HELPERS_H_
 
 // This file contains class definitions for the wrapping of C++ std::functions
-// in Java. It is #included by java/functions.i.
+// in Java. It is #included by java/functions.swig.
 
 #include <cstdint>
 #include <string>
diff --git a/ortools/util/java/BUILD.bazel b/ortools/util/java/BUILD.bazel
index 748abcbad6a..1496f519235 100644
--- a/ortools/util/java/BUILD.bazel
+++ b/ortools/util/java/BUILD.bazel
@@ -33,7 +33,7 @@ config_setting(
 filegroup(
     name = "vector_swig",
     srcs = [
-        "vector.i",
+        "vector.swig",
     ],
     visibility = ["//visibility:public"],
 )
@@ -49,7 +49,7 @@ filegroup(
 filegroup(
     name = "absl_string_view_swig",
     srcs = [
-        "absl_string_view.i",
+        "absl_string_view.swig",
     ],
     visibility = ["//visibility:public"],
 )
@@ -57,14 +57,14 @@ filegroup(
 filegroup(
     name = "sorted_interval_list_swig",
     srcs = [
-        "sorted_interval_list.i",
+        "sorted_interval_list.swig",
     ],
     visibility = ["//visibility:public"],
 )
 
 ortools_java_wrap_cc(
     name = "sorted_interval_list",
-    src = "sorted_interval_list.i",
+    src = "sorted_interval_list.swig",
     package = "com.google.ortools.util",
     swig_includes = [
         ":vector_swig",
diff --git a/ortools/util/java/CMakeLists.txt b/ortools/util/java/CMakeLists.txt
index 5964336095d..6f99f53adf7 100644
--- a/ortools/util/java/CMakeLists.txt
+++ b/ortools/util/java/CMakeLists.txt
@@ -11,17 +11,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-set_property(SOURCE sorted_interval_list.i PROPERTY CPLUSPLUS ON)
-set_property(SOURCE sorted_interval_list.i PROPERTY SWIG_MODULE_NAME main)
-set_property(SOURCE sorted_interval_list.i PROPERTY COMPILE_DEFINITIONS
+set_property(SOURCE sorted_interval_list.swig PROPERTY CPLUSPLUS ON)
+set_property(SOURCE sorted_interval_list.swig PROPERTY SWIG_MODULE_NAME main)
+set_property(SOURCE sorted_interval_list.swig PROPERTY COMPILE_DEFINITIONS
   ${OR_TOOLS_COMPILE_DEFINITIONS} ABSL_MUST_USE_RESULT=)
-set_property(SOURCE sorted_interval_list.i PROPERTY COMPILE_OPTIONS
+set_property(SOURCE sorted_interval_list.swig PROPERTY COMPILE_OPTIONS
   -package ${JAVA_PACKAGE}.util)
 swig_add_library(jniutil
   TYPE OBJECT
   LANGUAGE java
   OUTPUT_DIR ${JAVA_PROJECT_DIR}/${JAVA_SRC_PATH}/util
-  SOURCES sorted_interval_list.i)
+  SOURCES sorted_interval_list.swig)
 
 target_include_directories(jniutil PRIVATE ${JNI_INCLUDE_DIRS})
 set_target_properties(jniutil PROPERTIES
diff --git a/ortools/util/java/absl_string_view.i b/ortools/util/java/absl_string_view.swig
similarity index 99%
rename from ortools/util/java/absl_string_view.i
rename to ortools/util/java/absl_string_view.swig
index 311a31d40b2..6d3dc12ed03 100644
--- a/ortools/util/java/absl_string_view.i
+++ b/ortools/util/java/absl_string_view.swig
@@ -12,7 +12,7 @@
 // limitations under the License.
 
 /* -----------------------------------------------------------------------------
- * absl_string_view.i
+ * absl_string_view.swig
  *
  * Typemaps for absl::string_view
  * This is mapped to a Java String and is passed around by value.
diff --git a/ortools/util/java/functions.i b/ortools/util/java/functions.swig
similarity index 100%
rename from ortools/util/java/functions.i
rename to ortools/util/java/functions.swig
diff --git a/ortools/util/java/sorted_interval_list.i b/ortools/util/java/sorted_interval_list.swig
similarity index 98%
rename from ortools/util/java/sorted_interval_list.i
rename to ortools/util/java/sorted_interval_list.swig
index 97f38b0f10e..f9c1e07a097 100644
--- a/ortools/util/java/sorted_interval_list.i
+++ b/ortools/util/java/sorted_interval_list.swig
@@ -13,7 +13,7 @@
 
 // This is the java SWIG wrapper for ../sorted_interval_list.h.  See that file.
 
-%include "ortools/util/java/vector.i"
+%include "ortools/util/java/vector.swig"
 
 %{
 #include <cstdint>
diff --git a/ortools/util/java/tuple_set.i b/ortools/util/java/tuple_set.swig
similarity index 97%
rename from ortools/util/java/tuple_set.i
rename to ortools/util/java/tuple_set.swig
index 95e3d72c2c2..110eb497b57 100644
--- a/ortools/util/java/tuple_set.i
+++ b/ortools/util/java/tuple_set.swig
@@ -16,7 +16,7 @@
 
 %include "ortools/base/base.i"
 
-%include "ortools/util/java/vector.i"
+%include "ortools/util/java/vector.swig"
 
 %{
 // TODO(user): see if we can remove <vector>
diff --git a/ortools/util/java/vector.i b/ortools/util/java/vector.swig
similarity index 100%
rename from ortools/util/java/vector.i
rename to ortools/util/java/vector.swig
diff --git a/ortools/util/python/functions.i b/ortools/util/python/functions.swig
similarity index 100%
rename from ortools/util/python/functions.i
rename to ortools/util/python/functions.swig
diff --git a/ortools/util/python/pair.i b/ortools/util/python/pair.swig
similarity index 100%
rename from ortools/util/python/pair.i
rename to ortools/util/python/pair.swig
diff --git a/ortools/util/python/vector.i b/ortools/util/python/vector.swig
similarity index 100%
rename from ortools/util/python/vector.i
rename to ortools/util/python/vector.swig