diff --git a/cmake/download_googletest.cmake b/cmake/download_googletest.cmake
index 3570544..a9ea793 100644
--- a/cmake/download_googletest.cmake
+++ b/cmake/download_googletest.cmake
@@ -6,6 +6,7 @@ ExternalProject_Add(googletest_lib
   GIT_SHALLOW       ON
   SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
   BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
+  UPDATE_COMMAND    ""
   INSTALL_COMMAND   ""
   TEST_COMMAND      ""
   LOG_DOWNLOAD      ON
diff --git a/cmake/download_roc.cmake b/cmake/download_roc.cmake
index 86722dc..7be2250 100644
--- a/cmake/download_roc.cmake
+++ b/cmake/download_roc.cmake
@@ -33,6 +33,7 @@ ExternalProject_Add(roc_lib
   SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/roc-src"
   INSTALL_DIR "${CMAKE_CURRENT_BINARY_DIR}/roc-prefix"
   BUILD_IN_SOURCE ON
+  UPDATE_COMMAND    ""
   CONFIGURE_COMMAND ""
   BUILD_COMMAND ${SCONS_CMD}
   INSTALL_COMMAND ${SCONS_CMD} install