diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index b436c254ff0..ea0bc6d992e 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -2223,24 +2223,6 @@ namespace ts {
                 || (isES6ExportedDeclaration(node) && isFirstDeclarationOfKind(node, node.kind));
         }
 
-        /**
-         * Adds a leading VariableStatement for an enum or module declaration.
-         */
-        function addVarForEnumDeclaration(statements: Statement[], node: EnumDeclaration) {
-            // Emit a variable statement for the enum.
-            statements.push(
-                createVariableStatement(
-                    isES6ExportedDeclaration(node)
-                        ? visitNodes(node.modifiers, visitor, isModifier)
-                        : undefined,
-                    [createVariableDeclaration(
-                        getDeclarationName(node)
-                    )],
-                    /*location*/ node
-                )
-            );
-        }
-
         /**
          * Adds a trailing VariableStatement for an enum or module declaration.
          */
@@ -2271,7 +2253,7 @@ namespace ts {
 
             const statements: Statement[] = [];
             if (shouldEmitVarForEnumDeclaration(node)) {
-                addVarForEnumDeclaration(statements, node);
+                addVarForEnumOrModuleDeclaration(statements, node);
             }
 
             const localName = getGeneratedNameForNode(node);
@@ -2408,9 +2390,9 @@ namespace ts {
         }
 
         /**
-         * Adds a leading VariableStatement for a module declaration.
+         * Adds a leading VariableStatement for a enum or module declaration.
          */
-        function addVarForModuleDeclaration(statements: Statement[], node: ModuleDeclaration) {
+        function addVarForEnumOrModuleDeclaration(statements: Statement[], node: ModuleDeclaration | EnumDeclaration) {
             // Emit a variable statement for the module.
             statements.push(
                 setOriginalNode(
@@ -2421,7 +2403,21 @@ namespace ts {
                         [createVariableDeclaration(
                             getDeclarationName(node)
                         )],
-                        /*location*/ node
+                        // Trailing comments for module declaration should be emitted with function closure instead of variable statement
+                        // So do not set the end position for the variable statement node
+                        //     /** Module comment*/
+                        //     module m1 {
+                        //         function foo4Export() {
+                        //         }
+                        //     } // trailing comment module
+                        // Should emit
+                        //     /** Module comment*/
+                        //     var m1;
+                        //     (function (m1) {
+                        //         function foo4Export() {
+                        //         }
+                        //     })(m1 || (m1 = {})); // trailing comment module
+                        /*location*/ { pos: node.pos, end: -1 }
                     ),
                     node
                 )
@@ -2446,7 +2442,7 @@ namespace ts {
             const statements: Statement[] = [];
 
             if (shouldEmitVarForModuleDeclaration(node)) {
-                addVarForModuleDeclaration(statements, node);
+                addVarForEnumOrModuleDeclaration(statements, node);
             }
 
             const localName = getGeneratedNameForNode(node);