1 files changed, 10 insertions, 1 deletions
diff --git a/testing/mozharness/scripts/web_platform_tests.py b/testing/mozharness/scripts/web_platform_tests.py
index 4ce679f62d..5af71ad7ad 100755
--- a/testing/mozharness/scripts/web_platform_tests.py
+++ b/testing/mozharness/scripts/web_platform_tests.py
@@ -513,7 +513,16 @@ class WebPlatformTest(TestingMixin, MercurialScript, CodeCoverageMixin, AndroidM
         for tag in c["exclude_tag"]:
             cmd.append(f"--exclude-tag={tag}")
 
-        cmd.extend(test_paths)
+        if mozinfo.info["os"] == "win":
+            # Because of a limit on the length of CLI command line string length in Windows, we
+            # should prefer to pass paths by a file instead.
+            import tempfile
+
+            with tempfile.NamedTemporaryFile(delete=False) as tmp:
+                tmp.write("\n".join(test_paths).encode())
+                cmd.append(f"--include-file={tmp.name}")
+        else:
+            cmd.extend(test_paths)
 
         return cmd