diff --git a/ops/install_gcp_leoclean_nosend_release.py b/ops/install_gcp_leoclean_nosend_release.py
index 6f5c31e..ee60069 100644
--- a/ops/install_gcp_leoclean_nosend_release.py
+++ b/ops/install_gcp_leoclean_nosend_release.py
@@ -1156,10 +1156,16 @@ def _validate_starting_container(
         "container_security",
         "container_cap_drop_mismatch",
     )
+    cap_add = host.get("CapAdd")
+    normalized_cap_add = (
+        [item.removeprefix("CAP_") for item in cap_add]
+        if isinstance(cap_add, list) and all(isinstance(item, str) for item in cap_add)
+        else None
+    )
     _verification_require(
-        isinstance(host.get("CapAdd"), list)
-        and all(isinstance(item, str) for item in host["CapAdd"])
-        and sorted(host["CapAdd"]) == ["CHOWN", "SETGID", "SETPCAP", "SETUID"],
+        normalized_cap_add is not None
+        and len(normalized_cap_add) == len(set(normalized_cap_add))
+        and sorted(normalized_cap_add) == ["CHOWN", "SETGID", "SETPCAP", "SETUID"],
         "container_security",
         "container_cap_add_mismatch",
     )
diff --git a/tests/test_gcp_leoclean_nosend_installer.py b/tests/test_gcp_leoclean_nosend_installer.py
index d100c50..893b45f 100644
--- a/tests/test_gcp_leoclean_nosend_installer.py
+++ b/tests/test_gcp_leoclean_nosend_installer.py
@@ -725,6 +725,71 @@ def test_container_contract_failures_have_field_specific_bounded_codes(
     assert caught.value.failure_reason == failure_reason
 
 
+def test_container_cap_add_accepts_docker_28_canonical_names(tmp_path: Path) -> None:
+    bundle, release, image = release_bundle(tmp_path, "2")
+    paths = install_paths(tmp_path)
+    host = FakeHost(paths)
+    host.add_release(release, image)
+    installer.install_release(
+        bundle,
+        paths=paths,
+        source_binding=source_binding(),
+        runner=host,
+        sleeper=lambda _seconds: None,
+        execute_restart=True,
+    )
+    assert host.container is not None
+    host.container["HostConfig"]["CapAdd"] = [
+        "CAP_CHOWN",
+        "CAP_SETGID",
+        "CAP_SETPCAP",
+        "CAP_SETUID",
+    ]
+
+    verification = installer.verify_running_release(
+        release,
+        runner=host,
+        paths=paths,
+        sleeper=lambda _seconds: None,
+    )
+
+    assert verification["container_id"] == host.container["Id"]
+
+
+def test_container_cap_add_rejects_mixed_duplicate_names(tmp_path: Path) -> None:
+    bundle, release, image = release_bundle(tmp_path, "2")
+    paths = install_paths(tmp_path)
+    host = FakeHost(paths)
+    host.add_release(release, image)
+    installer.install_release(
+        bundle,
+        paths=paths,
+        source_binding=source_binding(),
+        runner=host,
+        sleeper=lambda _seconds: None,
+        execute_restart=True,
+    )
+    assert host.container is not None
+    host.container["HostConfig"]["CapAdd"] = [
+        "CHOWN",
+        "CAP_CHOWN",
+        "SETGID",
+        "SETPCAP",
+        "SETUID",
+    ]
+
+    with pytest.raises(installer.VerificationError) as caught:
+        installer.verify_running_release(
+            release,
+            runner=host,
+            paths=paths,
+            sleeper=lambda _seconds: None,
+        )
+
+    assert caught.value.failure_stage == "container_security"
+    assert caught.value.failure_reason == "container_cap_add_mismatch"
+
+
 def test_container_inspection_shape_has_bounded_code(tmp_path: Path) -> None:
     bundle, release, image = release_bundle(tmp_path, "2")
     paths = install_paths(tmp_path)