diff --git a/src/InjectionVisualizer/lexer.ts b/src/InjectionVisualizer/lexer.ts
index 033003b..60cb85c 100644
--- a/src/InjectionVisualizer/lexer.ts
+++ b/src/InjectionVisualizer/lexer.ts
@@ -1,9 +1,9 @@
 
 // source: https://www.regextester.com/?fam=110716
-const REGEX = /(\b(?:select|from|where|group|by|order|or|and|not|exists|having|join|left|right|inner)\b)|([A-Za-z][A-Za-z0-9]*)|([0-9]+\.[0-9]*)|([0-9]+)|('[^']*')|(\s+)|(\-\-[^\n\r]*)|([+\-\*/.=\(\),;])/gmi;
+const REGEX = /(\b(?:select|from|where|group|by|order|or|and|not|exists|having|join|left|right|inner)\b)|([A-Za-z][A-Za-z0-9]*)|([0-9]+\.[0-9]*)|([0-9]+)|('[^']*')|(\s+)|(\-\-[^\n\r]*)|([+\-\*/.=\(\),;])|(.)/gmi;
 
 export type Token = {
-  type: 'keyword' | 'identifier' | 'operator' | 'string' | 'integer' | 'decimal' | 'comment' | 'whitespace'
+  type: 'keyword' | 'identifier' | 'operator' | 'string' | 'integer' | 'decimal' | 'comment' | 'whitespace' | 'unknown'
   text: string
 }
 
@@ -16,7 +16,8 @@ const TOKEN_TYPES_BY_GROUP_INDEX: Array<Token['type'] | undefined> = [
   'string',
   'whitespace',
   'comment',
-  'operator'
+  'operator',
+  'unknown'
 ]
 
 export function tokenize(sql: string) {