diff --git a/contrib/check-commit b/contrib/check-commit
index a145161debed57abe149a7895fcd04bfe07ba369_Y29udHJpYi9jaGVjay1jb21taXQ=..8e805cf27caa48b4000887e4c40fdbacffe263b5_Y29udHJpYi9jaGVjay1jb21taXQ= 100755
--- a/contrib/check-commit
+++ b/contrib/check-commit
@@ -35,7 +35,7 @@
      "summary line doesn't start with 'topic: '"),
     (afterheader + r"[A-Z][a-z]\S+", "don't capitalize summary lines"),
     (afterheader + r"[^\n]*: *[A-Z][a-z]\S+", "don't capitalize summary lines"),
-    (afterheader + r"\S*[^A-Za-z0-9-]\S*: ",
+    (afterheader + r"\S*[^A-Za-z0-9-_]\S*: ",
      "summary keyword should be most user-relevant one-word command or topic"),
     (afterheader + r".*\.\s*\n", "don't add trailing period on summary line"),
     (afterheader + r".{79,}", "summary line too long (limit is 78)"),