diff --git a/src/core/unit.c b/src/core/unit.c
index d057b8ddc9..c706caae08 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -4629,7 +4629,7 @@ int unit_write_setting(Unit *u, UnitWriteFlags flags, const char *name, const ch
         /* Make sure the drop-in dir is registered in our path cache. This way we don't need to stupidly
          * recreate the cache after every drop-in we write. */
         if (u->manager->unit_path_cache) {
-                r = set_put_strdup(&u->manager->unit_path_cache, p);
+                r = set_put_strdup_full(&u->manager->unit_path_cache, &path_hash_ops_free, p);
                 if (r < 0)
                         return r;
         }