diff --git a/tools/enums.go b/tools/enums.go
index 47bffa1..bbda0df 100644
--- a/tools/enums.go
+++ b/tools/enums.go
@@ -124,6 +124,9 @@ func (d DataType) API() string { // API - Returns the API name of the data type
 }
 
 func (d DataType) String() string { // String - Returns the string name of the data type
+	if d < 0 {
+		return ""
+	}
 	return Str[d]
 }