diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index da73b668b6..e7f15e2ee7 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -2898,9 +2898,13 @@ int config_parse_compress(
                 void *data,
                 void *userdata) {
 
-        JournalCompressOptions* compress = data;
+        JournalCompressOptions* compress = ASSERT_PTR(data);
         int r;
 
+        assert(unit);
+        assert(filename);
+        assert(rvalue);
+
         if (isempty(rvalue)) {
                 compress->enabled = true;
                 compress->threshold_bytes = UINT64_MAX;