diff --git a/packages/bazel/src/esm5.bzl b/packages/bazel/src/esm5.bzl
index 8b7f3f3745..d21ef8cc2a 100644
--- a/packages/bazel/src/esm5.bzl
+++ b/packages/bazel/src/esm5.bzl
@@ -90,6 +90,7 @@ def _esm5_outputs_aspect(target, ctx):
             # TODO(alexeagle): enable worker mode for these compilations
             "supports-workers": "0",
         },
+        mnemonic = "ESM5",
     )
 
     root_dir = _join([