diff --git a/pretty.c b/pretty.c
index 5e162d7204..5e5ae45253 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1776,6 +1776,7 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 		}
 	trailer_out:
 		string_list_clear(&filter_list, 0);
+		strbuf_release(&kvsepbuf);
 		strbuf_release(&sepbuf);
 		return ret;
 	}
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 158b49d4b6..eb63ce011f 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -5,6 +5,8 @@
 #
 
 test_description='Test pretty formats'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Tested non-UTF-8 encoding