diff --git a/tagcmp.go b/tagcmp.go
index 2498a56..c991908 100644
--- a/tagcmp.go
+++ b/tagcmp.go
@@ -290,7 +290,7 @@ func patternMatches(tag string) error {
 
 	for _, pattern := range unsupported {
 		if match, _ := regexp.Match(pattern, []byte(tag)); match {
-			return fmt.Errorf("'%s' is not supported (%s)", tag, pattern)
+			return fmt.Errorf("version %s is not supported (matched: %s)", tag, pattern)
 		}
 	}