diff --git a/pkg/tokenizer/tokenizer.go b/pkg/tokenizer/tokenizer.go
index dbb113a..9161e57 100644
--- a/pkg/tokenizer/tokenizer.go
+++ b/pkg/tokenizer/tokenizer.go
@@ -14,7 +14,7 @@ func getToken(i *iterator.Iterator[rune]) (*Token, error) {
 
 	letter, err := i.Next()
 	if err != nil {
-		return nil, fmt.Errorf("Cannot produce next token: %w", err)
+		return nil, fmt.Errorf("cannot produce next token: %w", err)
 	}
 
 	// If it is an operand.