diff --git a/tools/regression/bin/sh/builtins/case10.0 b/tools/regression/bin/sh/builtins/case10.0
new file mode 100644
index 000000000000..a627b5cd996f
--- /dev/null
+++ b/tools/regression/bin/sh/builtins/case10.0
@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+case ! in
+[\!!]) ;;
+*) echo Failed at $LINENO ;;
+esac
+
+case ! in
+['!'!]) ;;
+*) echo Failed at $LINENO ;;
+esac
+
+case ! in
+["!"!]) ;;
+*) echo Failed at $LINENO ;;
+esac