diff --git a/components/engine/pkg/dockerscript/scanner/extra.go b/components/engine/pkg/dockerscript/scanner/extra.go
index 0b0ba1ae03..63302dc523 100644
--- a/components/engine/pkg/dockerscript/scanner/extra.go
+++ b/components/engine/pkg/dockerscript/scanner/extra.go
@@ -14,7 +14,7 @@ func detectIdent(ch rune) bool {
 	if unicode.IsDigit(ch) {
 		return true
 	}
-	if strings.ContainsRune("_:/+-@%^.", ch) {
+	if strings.ContainsRune("_:/+-@%^.!", ch) {
 		return true
 	}
 	return false