diff --git a/tests/popular_repos/popular_repos.bzl b/tests/popular_repos/popular_repos.bzl
index 88ba24f1c0..ac4d3eda78 100644
--- a/tests/popular_repos/popular_repos.bzl
+++ b/tests/popular_repos/popular_repos.bzl
@@ -19,41 +19,52 @@
 
 load("@io_bazel_rules_go//go/private:go_repository.bzl", "go_repository")
 
+def _maybe(repo_rule, name, **kwargs):
+  if name not in native.existing_rules():
+    repo_rule(name=name, **kwargs)
+
 def popular_repos():
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_x_crypto",
     importpath="golang.org/x/crypto",
     strip_prefix="crypto-81e90905daefcd6fd217b62423c0908922eadb30",
     type="zip",
     urls=['https://codeload.github.com/golang/crypto/zip/81e90905daefcd6fd217b62423c0908922eadb30'],
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_x_net",
     importpath="golang.org/x/net",
     commit="57efc9c3d9f91fb3277f8da1cff370539c4d3dc5",
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_x_sys",
     importpath="golang.org/x/sys",
     commit="0b25a408a50076fbbcae6b7ac0ea5fbb0b085e79",
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_x_text",
     importpath="golang.org/x/text",
     commit="a9a820217f98f7c8a207ec1e45a874e1fe12c478",
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_x_tools",
     importpath="golang.org/x/tools",
     commit="663269851cdddc898f963782f74ea574bcd5c814",
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="org_golang_google_grpc",
     importpath="google.golang.org/grpc",
     commit="3f10311ccf076b6b7cba28273df3290d42e60982",
     build_file_proto_mode="disable",
   )
-  go_repository(
+  _maybe(
+    go_repository,
     name="com_github_mattn_go_sqlite3",
     importpath="github.com/mattn/go-sqlite3",
     commit="83772a7051f5e30d8e59746a9e43dfa706b72f3b",
diff --git a/tests/popular_repos/popular_repos.py b/tests/popular_repos/popular_repos.py
index 1ccdf98d42..22000107a0 100755
--- a/tests/popular_repos/popular_repos.py
+++ b/tests/popular_repos/popular_repos.py
@@ -156,6 +156,10 @@
 BZL_HEADER = COPYRIGHT_HEADER + """
 load("@io_bazel_rules_go//go/private:go_repository.bzl", "go_repository")
 
+def _maybe(repo_rule, name, **kwargs):
+  if name not in native.existing_rules():
+    repo_rule(name=name, **kwargs)
+
 def popular_repos():
 """
 
@@ -165,7 +169,7 @@ def popular_repos_bzl():
   with open("popular_repos.bzl", "w") as f:
     f.write(BZL_HEADER)
     for repo in POPULAR_REPOS:
-      f.write("  go_repository(\n")
+      f.write("  _maybe(\n    go_repository,\n")
       for k in ["name", "importpath", "commit", "strip_prefix", "type", "build_file_proto_mode"]:
         if k in repo: f.write('    {}="{}",\n'.format(k, repo[k]))
       for k in ["urls"]: