diff --git a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
index 550b33a4c..0b8969b47 100644
--- a/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
+++ b/tool/src/org/antlr/v4/semantics/SemanticPipeline.java
@@ -151,7 +151,10 @@ public class SemanticPipeline {
 	void assignLexerTokenTypes(Grammar g, List<GrammarAST> tokensDefs) {
 		Grammar G = g.getOutermostGrammar(); // put in root, even if imported
 		for (GrammarAST def : tokensDefs) {
-			if ( def.getType()== ANTLRParser.TOKEN_REF ) G.defineTokenName(def.getText());
+			// tokens { id (',' id)* } so must check IDs not TOKEN_REF
+			if ( Grammar.isTokenName(def.getText()) ) {
+				G.defineTokenName(def.getText());
+			}
 		}
 
 		/* Define token types for nonfragment rules which do not include a 'type(...)'