diff --git a/sunrise-commit b/sunrise-commit
index 49cde82..76b9991 100755
--- a/sunrise-commit
+++ b/sunrise-commit
@@ -249,6 +249,9 @@ main() {
 				commitmsg=${commitmsg+${commitmsg} }${@}
 				break
 				;;
+			-*)
+				die "Unknown option: ${1}; see --help." >&2
+				;;
 			*)
 				commitmsg=${commitmsg+${commitmsg} }${1}
 				;;