diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/JavaScript/JavaScript.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/JavaScript/JavaScript.stg
index f143bbd38..728db6307 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/JavaScript/JavaScript.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/JavaScript/JavaScript.stg
@@ -36,12 +36,12 @@
  *  REQUIRED.
  */
 
-pythonTypeInitMap ::= [
-	"bool":"False",
+javascriptTypeInitMap ::= [
+	"bool":"false",
 	"int":"0",
 	"float":"0.0",
 	"str":"",
-	default:"None" // anything other than a primitive type is an object
+	default:"{}" // anything other than a primitive type is an object
 ]
 
 // args must be <object-model-object>, <fields-resulting-in-STs>
@@ -863,7 +863,7 @@ var serializedATN = ["<model.serialized; wrap={",<\n>    "}>"].join("");
  *	must be an object, default value is "null".
  */
 initValue(typeName) ::= <<
-<javaTypeInitMap.(typeName)>
+<javacriptTypeInitMap.(typeName)>
 >>
 
 codeFileExtension() ::= ".js"
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Python2/Python2.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Python2/Python2.stg
index b01a76fc4..570f1659f 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Python2/Python2.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Python2/Python2.stg
@@ -809,7 +809,7 @@ def serializedATN():
  *  must be an object, default value is "null".
  */
 initValue(typeName) ::= <<
-<javaTypeInitMap.(typeName)>
+<pythonTypeInitMap.(typeName)>
 >>
 
 codeFileExtension() ::= ".py"
diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Python3/Python3.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Python3/Python3.stg
index 081e3f3f1..34e525b85 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Python3/Python3.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Python3/Python3.stg
@@ -816,7 +816,7 @@ def serializedATN():
  *  must be an object, default value is "null".
  */
 initValue(typeName) ::= <<
-<javaTypeInitMap.(typeName)>
+<pythonTypeInitMap.(typeName)>
 >>
 
 codeFileExtension() ::= ".py"