diff --git a/.github/workflows/cron-images-mirror-all.yml b/.github/workflows/cron-images-mirror-all.yml
index 97199aada5..a09a4ed028 100644
--- a/.github/workflows/cron-images-mirror-all.yml
+++ b/.github/workflows/cron-images-mirror-all.yml
@@ -22,7 +22,7 @@ on:
         default: "."
         type: string
       images_per_hour:
-        description: "⏱️ Optional throttle: max images mirrored per hour"
+        description: "⏱️ Optional throttle: max Docker Hub copies per hour (default 150)"
         required: false
         type: string
       issues:
@@ -48,7 +48,7 @@ on:
         type: string
         default: "."
       images_per_hour:
-        description: "Optional throttle: max images mirrored per hour"
+        description: "Optional throttle: max Docker Hub copies per hour (default 150)"
         required: false
         type: string
       issues:
@@ -79,7 +79,7 @@ jobs:
     env:
       DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
       DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
-      IMAGES_PER_HOUR: ${{ github.event.inputs.images_per_hour || inputs.images_per_hour || '50' }}
+      IMAGES_PER_HOUR: ${{ github.event.inputs.images_per_hour || inputs.images_per_hour || '150' }}
 
     steps:
       - name: ⬇️ Checkout
diff --git a/cli/contributing/mirror/sync/__main__.py b/cli/contributing/mirror/sync/__main__.py
index d453732b46..6973670eef 100644
--- a/cli/contributing/mirror/sync/__main__.py
+++ b/cli/contributing/mirror/sync/__main__.py
@@ -70,7 +70,7 @@ def main() -> int:
         "--images-per-hour",
         type=_validate_positive_int,
         default=None,
-        help="Optional throttle: max images to mirror per hour (best-effort).",
+        help="Optional throttle: max Docker Hub copies per hour (best-effort); other registries are not throttled.",
     )
     args = parser.parse_args()
 
@@ -83,11 +83,6 @@ def main() -> int:
     last_start_ts: float | None = None
 
     for img in chain(iter_role_images(repo_root), iter_runner_images(repo_root)):
-        last_start_ts = _throttle_before_next_copy(
-            images_per_hour=args.images_per_hour,
-            last_start_ts=last_start_ts,
-        )
-
         total += 1
         src = f"docker://{img.source}"
         dest = f"docker://{provider.image_base(img)}:{img.version}"
@@ -101,6 +96,11 @@ def main() -> int:
                 )
                 continue
 
+            if img.registry == "docker.io":
+                last_start_ts = _throttle_before_next_copy(
+                    images_per_hour=args.images_per_hour,
+                    last_start_ts=last_start_ts,
+                )
             print(f"[mirror] {label}: {src} -> {dest}", flush=True)
             provider.mirror(img)
 
diff --git a/tests/unit/python/cli/contributing/mirror/test_sync.py b/tests/unit/python/cli/contributing/mirror/test_sync.py
index 2f8860eb69..31b8877077 100644
--- a/tests/unit/python/cli/contributing/mirror/test_sync.py
+++ b/tests/unit/python/cli/contributing/mirror/test_sync.py
@@ -7,6 +7,57 @@ import cli.contributing.mirror.sync.__main__ as sync_main
 from cli.contributing.mirror.model import ImageRef
 
 
+class TestThrottle(unittest.TestCase):
+    def test_only_docker_hub_copies_wait_for_the_throttle(self) -> None:
+        def image(name: str, registry: str) -> ImageRef:
+            return ImageRef(
+                role="r",
+                service=name,
+                name=name,
+                version="1",
+                source=f"{registry}/{name}:1",
+                registry=registry,
+            )
+
+        images = [
+            image("a", "docker.io"),
+            image("b", "ghcr.io"),
+            image("c", "quay.io"),
+            image("d", "docker.io"),
+        ]
+        with (
+            patch(
+                "cli.contributing.mirror.sync.__main__.iter_role_images",
+                return_value=images,
+            ),
+            patch(
+                "cli.contributing.mirror.sync.__main__.iter_runner_images",
+                return_value=[],
+            ),
+            patch.object(sync_main.GHCRProvider, "image_base", return_value="g/x"),
+            patch.object(sync_main.GHCRProvider, "mirror") as mock_mirror,
+            patch.object(sync_main.time, "monotonic", return_value=0.0),
+            patch.object(sync_main.time, "sleep") as mock_sleep,
+            patch(
+                "sys.argv",
+                [
+                    "mirror-sync",
+                    "--ghcr-namespace",
+                    "acme",
+                    "--ghcr-repository",
+                    "myrepo",
+                    "--images-per-hour",
+                    "150",
+                ],
+            ),
+        ):
+            result = sync_main.main()
+
+        self.assertEqual(result, 0)
+        self.assertEqual(mock_mirror.call_count, 4)
+        self.assertEqual([call.args for call in mock_sleep.call_args_list], [(24.0,)])
+
+
 class TestMirrorSync(unittest.TestCase):
     def test_only_missing_skips_existing_destination(self) -> None:
         image = ImageRef(