diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index c89f3c9c..ad15d937 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -1000,7 +1000,7 @@ cleanup:
 	{
 		int ret = b->ret;
 		FREE(b->line);
-		memset(b, 0, sizeof(b));
+		memset(b, 0, sizeof(struct archive_read_buffer));
 		return ret;
 	}
 }