diff --git a/tool/src/main/java/org/antlr/codegen/CodeGenerator.java b/tool/src/main/java/org/antlr/codegen/CodeGenerator.java
index b279bd565..df940ebf7 100644
--- a/tool/src/main/java/org/antlr/codegen/CodeGenerator.java
+++ b/tool/src/main/java/org/antlr/codegen/CodeGenerator.java
@@ -861,10 +861,11 @@ protected void genTokenTypeConstants(ST code) {
 	protected void genTokenTypeNames(ST code) {
 		for (int t=Label.MIN_TOKEN_TYPE; t<=grammar.getMaxTokenType(); t++) {
 			String tokenName = grammar.getTokenDisplayName(t);
-			if ( tokenName!=null ) {
+			if (tokenName != null) {
 				tokenName=target.getTargetStringLiteralFromString(tokenName, true);
-				code.add("tokenNames", tokenName);
 			}
+
+			code.add("tokenNames", tokenName);
 		}
 	}
 
diff --git a/tool/src/main/java/org/antlr/tool/AssignTokenTypesBehavior.java b/tool/src/main/java/org/antlr/tool/AssignTokenTypesBehavior.java
index cc7c0f4e1..6b56b6a27 100644
--- a/tool/src/main/java/org/antlr/tool/AssignTokenTypesBehavior.java
+++ b/tool/src/main/java/org/antlr/tool/AssignTokenTypesBehavior.java
@@ -271,9 +271,14 @@ protected void aliasTokenIDsAndLiterals(Grammar root) {
 			String tokenID = entry.getKey();
 			String literal = entry.getValue();
 			if ( literal.charAt(0)=='\'' && stringLiterals.get(literal)!=null ) {
-				stringLiterals.put(literal, tokens.get(tokenID));
-				// an alias still means you need a lexer rule for it
 				Integer typeI = tokens.get(tokenID);
+				if (typeI == null) {
+					// must have been imported from a tokenVocab
+					typeI = grammar.composite.tokenIDToTypeMap.get(tokenID);
+				}
+
+				stringLiterals.put(literal, typeI);
+				// an alias still means you need a lexer rule for it
 				if ( !tokenRuleDefs.contains(tokenID) ) {
 					root.defineLexerRuleForAliasedStringLiteral(tokenID, literal, typeI);
 				}
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/ActionScript/ActionScript.stg b/tool/src/main/resources/org/antlr/codegen/templates/ActionScript/ActionScript.stg
index 1fdeadc95..436061ca8 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/ActionScript/ActionScript.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/ActionScript/ActionScript.stg
@@ -173,7 +173,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 public class <grammar.recognizerName> extends <if(actions.(actionScope).superClass)><actions.(actionScope).superClass><else><@superClassName><superClass><@end><endif> {
 <if(grammar.grammarIsRoot)>
     public static const tokenNames:Array = [
-        "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">
+        "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">
     ];<\n>
 <endif>
     <tokens:{it |public static const <it.name>:int=<it.type>;}; separator="\n">
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/C/C.stg b/tool/src/main/resources/org/antlr/codegen/templates/C/C.stg
index 63646a707..5e7ae0f40 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/C/C.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/C/C.stg
@@ -1195,7 +1195,7 @@ pANTLR3_UINT8   <name>TokenNames[<length(tokenNames)>+4]
         (pANTLR3_UINT8) "\<EOR>",
         (pANTLR3_UINT8) "\<DOWN>",
         (pANTLR3_UINT8) "\<UP>",
-        <tokenNames:{it |(pANTLR3_UINT8) <it>}; separator=",\n">
+        <tokenNames:{it |(pANTLR3_UINT8) <it>}; separator=",\n", null="(pANTLR3_UINT8) \"<invalid>\"">
        };
 <endif>
 
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/CSharp2/CSharp2.stg b/tool/src/main/resources/org/antlr/codegen/templates/CSharp2/CSharp2.stg
index 8f15ef271..c037dc6b2 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/CSharp2/CSharp2.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/CSharp2/CSharp2.stg
@@ -287,7 +287,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 {
 <if(grammar.grammarIsRoot)>
 	internal static readonly string[] tokenNames = new string[] {
-		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">
+		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">
 	};
 <endif>
 	<tokens:{it|public const int <it.name; format="id">=<it.type>;}; separator="\n">
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/CSharp3/CSharp3.stg b/tool/src/main/resources/org/antlr/codegen/templates/CSharp3/CSharp3.stg
index c9229e176..247e9e0d6 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/CSharp3/CSharp3.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/CSharp3/CSharp3.stg
@@ -282,7 +282,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 {
 <if(grammar.grammarIsRoot)>
 	internal static readonly string[] tokenNames = new string[] {
-		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">
+		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">
 	};
 <endif>
 	<tokens:{it|public const int <it.name; format="id">=<it.type>;}; separator="\n">
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Cpp/Cpp.stg b/tool/src/main/resources/org/antlr/codegen/templates/Cpp/Cpp.stg
index d94024b7d..74f935f0a 100755
--- a/tool/src/main/resources/org/antlr/codegen/templates/Cpp/Cpp.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Cpp/Cpp.stg
@@ -821,7 +821,7 @@ ANTLR_UINT8* <name>TokenNames[<length(tokenNames)>+4]
         (ANTLR_UINT8*) "\<EOR>",
         (ANTLR_UINT8*) "\<DOWN>",
         (ANTLR_UINT8*) "\<UP>",
-        <tokenNames:{it |(ANTLR_UINT8*) <it>}; separator=",\n">
+        <tokenNames:{it |(ANTLR_UINT8*) <it>}; separator=",\n", null="(ANTLR_UINT8*) \"<invalid>\"">
        };
 <endif>
 
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Delphi/Delphi.stg b/tool/src/main/resources/org/antlr/codegen/templates/Delphi/Delphi.stg
index 7390fde6b..cafe524d9 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Delphi/Delphi.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Delphi/Delphi.stg
@@ -321,7 +321,7 @@ type
         '\<EOR>',
         '\<DOWN>',
         '\<UP>',
-        <tokenNames; separator=",\n">);<\n>
+        <tokenNames; separator=",\n", null="'<invalid>'">);<\n>
 <endif>
   public
     const
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Java/Java.stg b/tool/src/main/resources/org/antlr/codegen/templates/Java/Java.stg
index c4cc8d405..dbf98004e 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Java/Java.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Java/Java.stg
@@ -208,7 +208,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 public class <grammar.recognizerName> extends <@superClassName><superClass><@end> {
 <if(grammar.grammarIsRoot)>
 	public static final String[] tokenNames = new String[] {
-		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", wrap="\n\t\t">
+		"\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; null="\"<invalid>\"", separator=", ", wrap="\n\t\t">
 	};
 <endif>
 	<tokens:{it |public static final int <it.name>=<it.type>;}; separator="\n">
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/JavaScript/JavaScript.stg b/tool/src/main/resources/org/antlr/codegen/templates/JavaScript/JavaScript.stg
index 73cbaf42c..f63e1aa32 100755
--- a/tool/src/main/resources/org/antlr/codegen/templates/JavaScript/JavaScript.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/JavaScript/JavaScript.stg
@@ -217,7 +217,7 @@ org.antlr.lang.augmentObject(<grammar.recognizerName>.prototype, {
 // public class variables
 org.antlr.lang.augmentObject(<grammar.recognizerName>, {
 <if(grammar.grammarIsRoot)>
-    tokenNames: ["\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">],<\n>
+    tokenNames: ["\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">],<\n>
 <endif>
     <bitsets:bitset(name={FOLLOW_<it.name>_in_<it.inName><it.tokenIndex>},
                     words64=it.bits); separator=",\n">
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/ObjC/ObjC.stg b/tool/src/main/resources/org/antlr/codegen/templates/ObjC/ObjC.stg
index 369310a4c..dc0b55010 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/ObjC/ObjC.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/ObjC/ObjC.stg
@@ -712,7 +712,7 @@ genericParser(  grammar,
 {
     #pragma mark Bitsets
     <bitsets:{it | <bitsetInit(name={FOLLOW_<it.name>_in_<it.inName><it.tokenIndex>}, words64=it.bits)>}>
-    [BaseRecognizer setTokenNames:[[AMutableArray arrayWithObjects:@"\<invalid>", @"\<EOR>", @"\<DOWN>", @"\<UP>", <tokenNames:{it | @<it>}; separator=", ", wrap="\n ">, nil] retain]];
+    [BaseRecognizer setTokenNames:[[AMutableArray arrayWithObjects:@"\<invalid>", @"\<EOR>", @"\<DOWN>", @"\<UP>", <tokenNames:{it | @<it>}; separator=", ", null="@\"<invalid>\"", wrap="\n ">, nil] retain]];
     [BaseRecognizer setGrammarFileName:@"<fileName>"];
     <synpreds:{pred | <synpred(pred)>}>
 }
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Perl5/Perl5.stg b/tool/src/main/resources/org/antlr/codegen/templates/Perl5/Perl5.stg
index 1eb08ee2d..d6645067f 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Perl5/Perl5.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Perl5/Perl5.stg
@@ -201,7 +201,7 @@ use Moose;
 extends '<@superClassName><superClass><@end>';
 
 Readonly my $token_names => [
-    "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">
+    "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">
 ];
 
 use constant {
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Python/Python.stg b/tool/src/main/resources/org/antlr/codegen/templates/Python/Python.stg
index cffdf8677..f4c43cac2 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Python/Python.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Python/Python.stg
@@ -227,7 +227,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 # token names
 tokenNames = [
     "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>",
-    <tokenNames; wrap, separator=", ">
+    <tokenNames; wrap, separator=", ", null="\"<invalid>\"">
 ]<\n>
 <else>
 from <grammar.composite.rootGrammar.recognizerName> import tokenNames<\n>
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Python3/Python3.stg b/tool/src/main/resources/org/antlr/codegen/templates/Python3/Python3.stg
index ad2e2abf7..8f399e0e8 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Python3/Python3.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Python3/Python3.stg
@@ -229,7 +229,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 # token names
 tokenNames = [
     "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>",
-    <tokenNames; wrap, separator=", ">
+    <tokenNames; wrap, separator=", ", null="\"<invalid>\"">
 ]
 
 <scopes:{it|<if(it.isDynamicGlobalScope)><globalAttributeScopeClass(scope=it)><endif>}>
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Ruby/Ruby.stg b/tool/src/main/resources/org/antlr/codegen/templates/Ruby/Ruby.stg
index d74362374..75f3363e6 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Ruby/Ruby.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Ruby/Ruby.stg
@@ -118,7 +118,7 @@ module TokenData
   # this is necessary because anonymous tokens, which are
   # created from literal values in the grammar, do not
   # have descriptive names
-  register_names( <tokenNames:{it | <it>}; separator=", ", anchor, wrap="\n"> )
+  register_names( <tokenNames:{it | <it>}; separator=", ", null="\"<invalid>\"", anchor, wrap="\n"> )
 
 <endif>
 
diff --git a/tool/src/main/resources/org/antlr/codegen/templates/Scala/Scala.stg b/tool/src/main/resources/org/antlr/codegen/templates/Scala/Scala.stg
index bfd7c44aa..96066d608 100644
--- a/tool/src/main/resources/org/antlr/codegen/templates/Scala/Scala.stg
+++ b/tool/src/main/resources/org/antlr/codegen/templates/Scala/Scala.stg
@@ -185,7 +185,7 @@ genericParser(grammar, name, scopes, tokens, tokenNames, rules, numRules,
 object <grammar.recognizerName> {
 <if(grammar.grammarIsRoot)>
     val tokenNames = Array(
-        "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ">
+        "\<invalid>", "\<EOR>", "\<DOWN>", "\<UP>", <tokenNames; separator=", ", null="\"<invalid>\"">
     )<\n>
 <endif>
 
diff --git a/tool/src/test/java/org/antlr/test/TestJavaCodeGeneration.java b/tool/src/test/java/org/antlr/test/TestJavaCodeGeneration.java
index 5a189cdd4..b8dd7ecae 100644
--- a/tool/src/test/java/org/antlr/test/TestJavaCodeGeneration.java
+++ b/tool/src/test/java/org/antlr/test/TestJavaCodeGeneration.java
@@ -158,4 +158,136 @@ public void testSemanticPredicateAnalysisStackOverflow() throws Exception {
 		boolean success = rawGenerateAndBuildRecognizer("T.g", grammar, "TParser", "TLexer", false);
 		assertTrue(success);
 	}
+
+	/**
+	 * This is a regression test for antlr/antlr3#157 "missing lexer rules if
+	 * tokenVocab defined"
+	 * https://github.com/antlr/antlr3/pull/157
+	 */
+	@Test public void testImportedTokensInCombinedGrammar() {
+		String tokensFile =
+			"TypeArray=394\n" +
+			"Null=395\n";
+		System.out.println("dir " + tmpdir);
+		mkdir(tmpdir);
+		writeFile(tmpdir, "CustomVocab.tokens", tokensFile);
+
+		String grammar =
+			"grammar T;\n" +
+			"options { output = AST; tokenVocab = CustomVocab; }\n" +
+			"tokens { TypeArray = 'array'; }\n" +
+			"a : ('array' TypeArray 'null' Null ID)* EOF\n" +
+			"    {System.out.println(tokenNames[TypeArray] + \"=\" + TypeArray);\n" +
+			"     System.out.println(tokenNames[Null] + \"=\" + Null);};\n" +
+			"Null : 'null';\n" +
+			"ID : 'a'..'z'+;\n" +
+			"WS : ' '+ {skip();};\n";
+		String input = "array array null null foo";
+		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", input, false);
+		String expected =
+			"TypeArray=394\n" +
+			"Null=395\n" +
+			"array array null null foo <EOF>\n";
+		assertEquals(expected, found);
+		assertNull(stderrDuringParse);
+	}
+
+	/**
+	 * This is a regression test for antlr/antlr3#157 "missing lexer rules if
+	 * tokenVocab defined"
+	 * https://github.com/antlr/antlr3/pull/157
+	 */
+	@Test public void testImportedTokensInCombinedGrammarNoReferences() {
+		String tokensFile =
+			"TypeArray=394\n" +
+			"Null=395\n";
+		System.out.println("dir " + tmpdir);
+		mkdir(tmpdir);
+		writeFile(tmpdir, "CustomVocab.tokens", tokensFile);
+
+		String grammar =
+			"grammar T;\n" +
+			"options { output = AST; tokenVocab = CustomVocab; }\n" +
+			"tokens { TypeArray = 'array'; }\n" +
+			"a : (ID)* EOF\n" +
+			"    {System.out.println(tokenNames[TypeArray] + \"=\" + TypeArray);\n" +
+			"     System.out.println(tokenNames[Null] + \"=\" + Null);};\n" +
+			"Null : 'null';\n" +
+			"ID : 'a'..'z'+;\n" +
+			"WS : ' '+ {skip();};\n";
+		String input = "foo";
+		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", input, false);
+		String expected =
+			"TypeArray=394\n" +
+			"Null=395\n" +
+			"foo <EOF>\n";
+		assertEquals(expected, found);
+		assertNull(stderrDuringParse);
+	}
+
+	/**
+	 * This is a regression test for antlr/antlr3#157 "missing lexer rules if
+	 * tokenVocab defined"
+	 * https://github.com/antlr/antlr3/pull/157
+	 */
+	@Test public void testImportedTokensInCombinedGrammarLiteralReferencesOnly() {
+		String tokensFile =
+			"TypeArray=394\n" +
+			"Null=395\n";
+		System.out.println("dir " + tmpdir);
+		mkdir(tmpdir);
+		writeFile(tmpdir, "CustomVocab.tokens", tokensFile);
+
+		String grammar =
+			"grammar T;\n" +
+			"options { output = AST; tokenVocab = CustomVocab; }\n" +
+			"tokens { TypeArray = 'array'; }\n" +
+			"a : ('array' 'null' ID)* EOF\n" +
+			"    {System.out.println(tokenNames[TypeArray] + \"=\" + TypeArray);\n" +
+			"     System.out.println(tokenNames[Null] + \"=\" + Null);};\n" +
+			"Null : 'null';\n" +
+			"ID : 'a'..'z'+;\n" +
+			"WS : ' '+ {skip();};\n";
+		String input = "array null foo";
+		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", input, false);
+		String expected =
+			"TypeArray=394\n" +
+			"Null=395\n" +
+			"array null foo <EOF>\n";
+		assertEquals(expected, found);
+		assertNull(stderrDuringParse);
+	}
+
+	/**
+	 * This is a regression test for antlr/antlr3#157 "missing lexer rules if
+	 * tokenVocab defined"
+	 * https://github.com/antlr/antlr3/pull/157
+	 */
+	@Test public void testImportedTokensInCombinedGrammarSymbolicReferencesOnly() {
+		String tokensFile =
+			"TypeArray=394\n" +
+			"Null=395\n";
+		System.out.println("dir " + tmpdir);
+		mkdir(tmpdir);
+		writeFile(tmpdir, "CustomVocab.tokens", tokensFile);
+
+		String grammar =
+			"grammar T;\n" +
+			"options { output = AST; tokenVocab = CustomVocab; }\n" +
+			"tokens { TypeArray = 'array'; }\n" +
+			"a : (TypeArray Null ID)* EOF\n" +
+			"    {System.out.println(tokenNames[TypeArray] + \"=\" + TypeArray);\n" +
+			"     System.out.println(tokenNames[Null] + \"=\" + Null);};\n" +
+			"Null : 'null';\n" +
+			"ID : 'a'..'z'+;\n" +
+			"WS : ' '+ {skip();};\n";
+		String input = "array null foo";
+		String found = execParser("T.g", grammar, "TParser", "TLexer", "a", input, false);
+		String expected =
+			"TypeArray=394\n" +
+			"Null=395\n" +
+			"array null foo <EOF>\n";
+		assertEquals(expected, found);
+		assertNull(stderrDuringParse);
+	}
 }