diff --git a/synthtool/gcp/templates/python_samples/noxfile.py.j2 b/synthtool/gcp/templates/python_samples/noxfile.py.j2
index 8e0f6c1fc..dfad4aaa5 100644
--- a/synthtool/gcp/templates/python_samples/noxfile.py.j2
+++ b/synthtool/gcp/templates/python_samples/noxfile.py.j2
@@ -96,6 +96,8 @@ IGNORED_VERSIONS = TEST_CONFIG['ignored_versions']
 
 TESTED_VERSIONS = sorted([v for v in ALL_VERSIONS if v not in IGNORED_VERSIONS])
 
+INSTALL_LIBRARY_FROM_SOURCE = os.environ.get(bool("INSTALL_LIBRARY_FROM_SOURCE", False)
+
 #
 # Style Checks
 #
@@ -161,7 +163,7 @@ def _session_tests(session, post_install=None):
     if os.path.exists("requirements-test.txt"):
         session.install("-r", "requirements-test.txt")
     
-    if _is_client_library_repo():
+    if _is_client_library_repo() and INSTALL_LIBRARY_FROM_SOURCE:
         session.install('-e', _get_repo_root())
 
     if post_install: