diff --git a/src/basic/strbuf.c b/src/basic/strbuf.c
index e2ed776a09..275a012b28 100644
--- a/src/basic/strbuf.c
+++ b/src/basic/strbuf.c
@@ -66,6 +66,9 @@ void strbuf_complete(struct strbuf *str) {
 
 /* clean up everything */
 void strbuf_cleanup(struct strbuf *str) {
+        if (!str)
+                return;
+
         strbuf_complete(str);
         free(str->buf);
         free(str);