diff --git a/src/main/antlr/Decaf.g4 b/src/main/antlr/Decaf.g4
index 0171f6e..f0e3a96 100644
--- a/src/main/antlr/Decaf.g4
+++ b/src/main/antlr/Decaf.g4
@@ -88,6 +88,6 @@ CHAR : 'char';
 
 BOOLEANLITERAL : 'true' | 'false' ;
 CHARLITERAL : ['][a-zA-Z]['];
-IDENTIFIER : [a-zA-Z]+;
+IDENTIFIER : ([a-zA-Z]+[0-9]*)+;
 NUMBER : [0-9]+;
 WS : [ \t\r\n] -> skip;