diff --git a/synthtool/gcp/templates/python_library/noxfile.py.j2 b/synthtool/gcp/templates/python_library/noxfile.py.j2
index ed5f9fcb4..6cba976ad 100644
--- a/synthtool/gcp/templates/python_library/noxfile.py.j2
+++ b/synthtool/gcp/templates/python_library/noxfile.py.j2
@@ -243,6 +243,7 @@ def unit(session, protobuf_implementation):
     )
     install_unittest_dependencies(session, "-c", constraints_path)
 
+    # TODO(https://github.com/googleapis/synthtool/issues/1976):
     # Remove the 'cpp' implementation once support for Protobuf 3.x is dropped.
     # The 'cpp' implementation requires Protobuf<4.
     if protobuf_implementation == "cpp":
diff --git a/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2 b/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
index 3f856cb38..b4ab177fe 100644
--- a/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
+++ b/synthtool/gcp/templates/python_mono_repo_library/noxfile.py.j2
@@ -248,6 +248,7 @@ def unit(session, protobuf_implementation):
     )
     install_unittest_dependencies(session, "-c", constraints_path)
 
+    # TODO(https://github.com/googleapis/synthtool/issues/1976):
     # Remove the 'cpp' implementation once support for Protobuf 3.x is dropped.
     # The 'cpp' implementation requires Protobuf<4.
     if protobuf_implementation == "cpp":