diff --git a/vinca/naming.py b/vinca/naming.py
index 39f6ea2..b3db5ae 100644
--- a/vinca/naming.py
+++ b/vinca/naming.py
@@ -2,6 +2,8 @@
 
 from enum import Enum
 
+from vinca.mutex import get_mutex_package_dependency
+
 
 class PackageNameMode(str, Enum):
     """Supported ROS package naming transition modes."""
@@ -81,10 +83,17 @@ def generate_legacy_compatibility_output(output, pkg_shortname, distro, vinca_co
 
     legacy_name = get_legacy_package_name(pkg_shortname, distro)
     version = output["package"]["version"]
+    run = [f"{canonical_name} =={version}"]
+    # Several distributions can publish the same ros2-<pkg> version to one channel;
+    # requiring this distribution's mutex (as the canonical packages do) keeps the
+    # alias from being satisfied by another distribution's build.
+    mutex_dependency = get_mutex_package_dependency(vinca_conf, distro)
+    if mutex_dependency:
+        run.append(mutex_dependency)
     return {
         "package": {"name": legacy_name, "version": version},
         "build": {"script": ""},
-        "requirements": {"run": [f"{canonical_name} =={version}"]},
+        "requirements": {"run": run},
         "about": {"summary": f"Compatibility package for {canonical_name}"},
     }
 
@@ -106,6 +115,6 @@ def is_legacy_compatibility_output(output, distro, vinca_conf):
     shortname = name[len(legacy_prefix) :]
     canonical_name = get_new_package_name(shortname, distro)
     version = output["package"]["version"]
-    return output.get("requirements", {}).get("run") == [
-        f"{canonical_name} =={version}"
-    ]
+    # the canonical package comes first, optionally followed by the mutex
+    run = output.get("requirements", {}).get("run") or []
+    return run[:1] == [f"{canonical_name} =={version}"]
diff --git a/vinca/test_naming_scheme.py b/vinca/test_naming_scheme.py
index 00d925b..32c939d 100644
--- a/vinca/test_naming_scheme.py
+++ b/vinca/test_naming_scheme.py
@@ -11,6 +11,7 @@
     generate_legacy_compatibility_output,
     get_package_name,
     get_package_name_mode,
+    is_legacy_compatibility_output,
 )
 from vinca.resolve import resolve_pkgname
 from vinca.utils import (
@@ -249,6 +250,40 @@ def test_both_mode_generates_legacy_compatibility_output():
     }
 
 
+@pytest.mark.parametrize(
+    "mutex_package,expected_mutex",
+    [
+        (
+            {
+                "name": "ros2-distro-mutex",
+                "version": "0.21.0",
+                "upper_bound": "x.x",
+                "run_constraints": [],
+            },
+            "ros2-distro-mutex 0.21.* humble_*",
+        ),
+        # legacy string form: the spec is used verbatim, as for canonical packages
+        ("ros2-distro-mutex 0.5.* humble", "ros2-distro-mutex 0.5.* humble"),
+    ],
+)
+def test_compatibility_output_requires_the_distribution_mutex(
+    mutex_package, expected_mutex
+):
+    distro = make_distro()
+    vinca_conf = {"package_name_mode": "both", "mutex_package": mutex_package}
+    output = {"package": {"name": "ros2-my-package", "version": "1.2.3"}}
+
+    compatibility_output = generate_legacy_compatibility_output(
+        output, "my_package", distro, vinca_conf
+    )
+
+    assert compatibility_output["requirements"]["run"] == [
+        "ros2-my-package ==1.2.3",
+        expected_mutex,
+    ]
+    assert is_legacy_compatibility_output(compatibility_output, distro, vinca_conf)
+
+
 @pytest.mark.parametrize("mode", ["legacy", "new"])
 def test_single_name_modes_do_not_generate_compatibility_output(mode):
     distro = make_distro()