diff --git a/builtin/log.c b/builtin/log.c
index 4389722b4b..e4d812208d 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -864,6 +864,7 @@ static void add_branch_description(struct strbuf *buf, const char *branch_name)
 		strbuf_addbuf(buf, &desc);
 		strbuf_addch(buf, '\n');
 	}
+	strbuf_release(&desc);
 }
 
 static char *find_branch_name(struct rev_info *rev)