diff --git a/tools/abi_check.py b/tools/abi_check.py
index bd3ba8dc..a77372c5 100644
--- a/tools/abi_check.py
+++ b/tools/abi_check.py
@@ -209,10 +209,12 @@ def headers(prefix):
 
 
 def _is_compatibility_package(rec: dict) -> bool:
-    """vinca's ros-<distro>-<pkg> packages (package_name_mode: both) are empty and
-    only depend on ros2-<pkg> of the same version."""
+    """vinca's ros-<distro>-<pkg> packages (package_name_mode: both) are empty and only
+    depend on ros2-<pkg> of the same version (and, since RoboStack/vinca#171, on the
+    distribution's mutex)."""
     deps = rec.get("depends", [])
-    return len(deps) == 1 and deps[0].startswith("ros2-") and "==" in deps[0]
+    return (bool(deps) and deps[0].startswith("ros2-") and "==" in deps[0]
+            and all(d.startswith("ros2-distro-mutex") for d in deps[1:]))
 
 
 def short_name(name: str, distro: str) -> str | None:
diff --git a/tools/tests/test_abi_check.py b/tools/tests/test_abi_check.py
index 6352cd23..f8b13009 100644
--- a/tools/tests/test_abi_check.py
+++ b/tools/tests/test_abi_check.py
@@ -42,3 +42,13 @@ def test_next_build_number_is_above_vinca_and_every_published_build(tmp_path, mo
     monkeypatch.setattr(rs, "DISTROS", tmp_path)
     assert abi_check.next_build_number({"a": {"1": {"build_number": 30}}, "b": {"2": {"build_number": 7}}}, "jazzy") == 31
     assert abi_check.next_build_number({"a": {"1": {"build_number": 3}}}, "jazzy") == 26
+
+
+def test_compatibility_packages_with_and_without_the_mutex():
+    assert abi_check._is_compatibility_package({"depends": ["ros2-rclcpp ==28.1.22"]})
+    assert abi_check._is_compatibility_package(
+        {"depends": ["ros2-rclcpp ==28.1.22", "ros2-distro-mutex 0.19.* jazzy_*"]})
+    assert not abi_check._is_compatibility_package(
+        {"depends": ["ros2-rclcpp ==28.1.22", "libboost >=1.90"]})
+    assert not abi_check._is_compatibility_package({"depends": ["ros2-distro-mutex 0.19.* jazzy_*", "libfoo"]})
+    assert not abi_check._is_compatibility_package({"depends": []})