diff --git a/js/private/js_binary.bzl b/js/private/js_binary.bzl
index 1e0a55382..0456212e3 100644
--- a/js/private/js_binary.bzl
+++ b/js/private/js_binary.bzl
@@ -559,11 +559,10 @@ def _js_binary_impl(ctx):
 
     providers = []
 
-    if ctx.attr.testonly and ctx.configuration.coverage_enabled:
+    if ctx.attr.testonly and ctx.configuration.coverage_enabled and hasattr(ctx.attr, "_is_test"):
         # We have to instruct rule implementers to have this attribute present.
         if not hasattr(ctx.attr, "_lcov_merger"):
             fail("_lcov_merger attribute is missing and coverage was requested")
-
         # We have to propagate _lcov_merger runfiles since bazel does not treat _lcov_merger as a proper tool.
         # See: https://github.com/bazelbuild/bazel/issues/4033
         runfiles = runfiles.merge(ctx.attr._lcov_merger[DefaultInfo].default_runfiles)
@@ -641,6 +640,9 @@ the contract between Bazel and a test runner.""",
             default = Label("//js/private/coverage:merger"),
             cfg = "exec",
         ),
+        "_is_test": attr.bool(
+            default = True
+        )
     }),
     test = True,
     toolchains = js_binary_lib.toolchains,