diff --git a/src/libsystemd/sd-path/path-lookup.c b/src/libsystemd/sd-path/path-lookup.c
index 55d9d4353a..3ae217a7c5 100644
--- a/src/libsystemd/sd-path/path-lookup.c
+++ b/src/libsystemd/sd-path/path-lookup.c
@@ -33,32 +33,54 @@ int user_search_dirs(const char *suffix, char ***ret_config_dirs, char ***ret_da
         return 0;
 }
 
-int runtime_directory(RuntimeScope scope, const char *suffix, char **ret) {
+int runtime_directory_generic(RuntimeScope scope, const char *suffix, char **ret) {
         int r;
 
-        assert(IN_SET(scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER));
-        assert(suffix);
         assert(ret);
 
-        /* Accept $RUNTIME_DIRECTORY as authoritative
+        /* This does not bother with $RUNTIME_DIRECTORY, and hence can be applied to get other service's
+         * runtime dir */
+
+        switch (scope) {
+        case RUNTIME_SCOPE_USER:
+                r = xdg_user_runtime_dir(suffix, ret);
+                if (r < 0)
+                        return r;
+                break;
+
+        case RUNTIME_SCOPE_SYSTEM: {
+                char *d = path_join("/run", suffix);
+                if (!d)
+                        return -ENOMEM;
+                *ret = d;
+                break;
+        }
+
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+int runtime_directory(RuntimeScope scope, const char *fallback_suffix, char **ret) {
+        int r;
+
+        assert(ret);
+
+        /* Accept $RUNTIME_DIRECTORY as authoritative, i.e. only works for our service's own runtime dir.
+         *
          * If it's missing, apply the suffix to /run/, or $XDG_RUNTIME_DIR if we are in a user runtime scope.
          *
-         * Return value indicates whether the suffix was applied or not */
+         * Return value indicates whether the suffix was applied or not. */
 
         const char *e = secure_getenv("RUNTIME_DIRECTORY");
         if (e)
                 return strdup_to(ret, e);
 
-        if (scope == RUNTIME_SCOPE_USER) {
-                r = xdg_user_runtime_dir(suffix, ret);
-                if (r < 0)
-                        return r;
-        } else {
-                char *d = path_join("/run", suffix);
-                if (!d)
-                        return -ENOMEM;
-                *ret = d;
-        }
+        r = runtime_directory_generic(scope, fallback_suffix, ret);
+        if (r < 0)
+                return r;
 
         return 1;
 }
diff --git a/src/libsystemd/sd-path/path-lookup.h b/src/libsystemd/sd-path/path-lookup.h
index 8457053339..b706e1a6df 100644
--- a/src/libsystemd/sd-path/path-lookup.h
+++ b/src/libsystemd/sd-path/path-lookup.h
@@ -57,7 +57,8 @@ int lookup_paths_init_or_warn(LookupPaths *lp, RuntimeScope scope, LookupPathsFl
 void lookup_paths_log(LookupPaths *p);
 void lookup_paths_done(LookupPaths *p);
 
-int runtime_directory(RuntimeScope scope, const char *suffix, char **ret);
+int runtime_directory_generic(RuntimeScope scope, const char *suffix, char **ret);
+int runtime_directory(RuntimeScope scope, const char *fallback_suffix, char **ret);
 
 /* We don't treat /etc/xdg/systemd/ in these functions as the xdg base dir spec suggests because we assume
  * that is a link to /etc/systemd/ anyway. */