diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index f9ff9545ddd..6f09301521b 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -169,8 +169,7 @@ JournalFile* journal_file_close(JournalFile *f) {
         safe_close(f->fd);
         free(f->path);
 
-        if (f->mmap)
-                mmap_cache_unref(f->mmap);
+        mmap_cache_unref(f->mmap);
 
         ordered_hashmap_free_free(f->chain_cache);
 
diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c
index 5a07ddda764..eb4b092e80a 100644
--- a/src/journal/mmap-cache.c
+++ b/src/journal/mmap-cache.c
@@ -348,7 +348,10 @@ static void mmap_cache_free(MMapCache *m) {
 }
 
 MMapCache* mmap_cache_unref(MMapCache *m) {
-        assert(m);
+
+        if (!m)
+                return NULL;
+
         assert(m->n_ref > 0);
 
         m->n_ref --;