diff --git a/src/core/transaction.c b/src/core/transaction.c
index c3d6ffccc1..65a00bd928 100644
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -325,6 +325,8 @@ static char* merge_unit_ids(const char* unit_log_field, char * const* pairs) {
         _cleanup_free_ char *ans = NULL;
         size_t size = 0;
 
+        assert(unit_log_field);
+
         STRV_FOREACH_PAIR(unit_id, job_type, pairs) {
                 size_t next;
 
diff --git a/src/shared/creds-util.c b/src/shared/creds-util.c
index 59f580775d..efc36e2d6d 100644
--- a/src/shared/creds-util.c
+++ b/src/shared/creds-util.c
@@ -342,6 +342,9 @@ int get_credential_host_secret(CredentialSecretFlags flags, void **ret, size_t *
                 filename = "credential.secret";
         }
 
+        assert(dirname);
+        assert(filename);
+
         mkdir_parents(dirname, 0755);
         dfd = open_mkdir_at(AT_FDCWD, dirname, O_CLOEXEC, 0755);
         if (dfd < 0)