diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 2f4c2194371..54376159784 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -88,7 +88,11 @@ namespace ts {
         let container: Node;
         let blockScopeContainer: Node;
         let lastContainer: Node;
-        let inStrictMode = false;
+
+        // If this file is an external module, then it is automatically in strict-mode according to
+        // ES6.  If it is not an external module, then we'll determine if it is in strict mode or 
+        // not depending on if we see "use strict" in certain places.
+        let inStrictMode = !!file.externalModuleIndicator;
 
         let symbolCount = 0;
         let Symbol = objectAllocator.getSymbolConstructor();
diff --git a/tests/baselines/reference/exportNonInitializedVariablesAMD.errors.txt b/tests/baselines/reference/exportNonInitializedVariablesAMD.errors.txt
index ae79675d8dd..27679cf6071 100644
--- a/tests/baselines/reference/exportNonInitializedVariablesAMD.errors.txt
+++ b/tests/baselines/reference/exportNonInitializedVariablesAMD.errors.txt
@@ -1,15 +1,18 @@
 tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts(2,4): error TS1123: Variable declaration list cannot be empty.
+tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts(3,1): error TS1212: Identifier expected. 'let' is a reserved word in strict mode
 tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts(3,1): error TS2304: Cannot find name 'let'.
 tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts(4,6): error TS1123: Variable declaration list cannot be empty.
 
 
-==== tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts (3 errors) ====
+==== tests/cases/conformance/externalModules/exportNonInitializedVariablesAMD.ts (4 errors) ====
     
     var;
        
 !!! error TS1123: Variable declaration list cannot be empty.
     let;
     ~~~
+!!! error TS1212: Identifier expected. 'let' is a reserved word in strict mode
+    ~~~
 !!! error TS2304: Cannot find name 'let'.
     const;
          
diff --git a/tests/baselines/reference/exportNonInitializedVariablesCommonJS.errors.txt b/tests/baselines/reference/exportNonInitializedVariablesCommonJS.errors.txt
index 65a18649af3..1b05c756d71 100644
--- a/tests/baselines/reference/exportNonInitializedVariablesCommonJS.errors.txt
+++ b/tests/baselines/reference/exportNonInitializedVariablesCommonJS.errors.txt
@@ -1,15 +1,18 @@
 tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts(2,4): error TS1123: Variable declaration list cannot be empty.
+tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts(3,1): error TS1212: Identifier expected. 'let' is a reserved word in strict mode
 tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts(3,1): error TS2304: Cannot find name 'let'.
 tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts(4,6): error TS1123: Variable declaration list cannot be empty.
 
 
-==== tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts (3 errors) ====
+==== tests/cases/conformance/externalModules/exportNonInitializedVariablesCommonJS.ts (4 errors) ====
     
     var;
        
 !!! error TS1123: Variable declaration list cannot be empty.
     let;
     ~~~
+!!! error TS1212: Identifier expected. 'let' is a reserved word in strict mode
+    ~~~
 !!! error TS2304: Cannot find name 'let'.
     const;
          
diff --git a/tests/baselines/reference/exportNonInitializedVariablesES6.errors.txt b/tests/baselines/reference/exportNonInitializedVariablesES6.errors.txt
index 905d16b360f..f0ae7a83a1d 100644
--- a/tests/baselines/reference/exportNonInitializedVariablesES6.errors.txt
+++ b/tests/baselines/reference/exportNonInitializedVariablesES6.errors.txt
@@ -1,15 +1,18 @@
 tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts(2,4): error TS1123: Variable declaration list cannot be empty.
+tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts(3,1): error TS1212: Identifier expected. 'let' is a reserved word in strict mode
 tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts(3,1): error TS2304: Cannot find name 'let'.
 tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts(4,6): error TS1123: Variable declaration list cannot be empty.
 
 
-==== tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts (3 errors) ====
+==== tests/cases/conformance/externalModules/exportNonInitializedVariablesES6.ts (4 errors) ====
     
     var;
        
 !!! error TS1123: Variable declaration list cannot be empty.
     let;
     ~~~
+!!! error TS1212: Identifier expected. 'let' is a reserved word in strict mode
+    ~~~
 !!! error TS2304: Cannot find name 'let'.
     const;
          
diff --git a/tests/baselines/reference/exportNonInitializedVariablesSystem.errors.txt b/tests/baselines/reference/exportNonInitializedVariablesSystem.errors.txt
index d7aeb5d2ac0..55249c36c75 100644
--- a/tests/baselines/reference/exportNonInitializedVariablesSystem.errors.txt
+++ b/tests/baselines/reference/exportNonInitializedVariablesSystem.errors.txt
@@ -1,15 +1,18 @@
 tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts(2,4): error TS1123: Variable declaration list cannot be empty.
+tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts(3,1): error TS1212: Identifier expected. 'let' is a reserved word in strict mode
 tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts(3,1): error TS2304: Cannot find name 'let'.
 tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts(4,6): error TS1123: Variable declaration list cannot be empty.
 
 
-==== tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts (3 errors) ====
+==== tests/cases/conformance/externalModules/exportNonInitializedVariablesSystem.ts (4 errors) ====
     
     var;
        
 !!! error TS1123: Variable declaration list cannot be empty.
     let;
     ~~~
+!!! error TS1212: Identifier expected. 'let' is a reserved word in strict mode
+    ~~~
 !!! error TS2304: Cannot find name 'let'.
     const;
          
diff --git a/tests/baselines/reference/exportNonInitializedVariablesUMD.errors.txt b/tests/baselines/reference/exportNonInitializedVariablesUMD.errors.txt
index eaf68e67055..b21d9a89715 100644
--- a/tests/baselines/reference/exportNonInitializedVariablesUMD.errors.txt
+++ b/tests/baselines/reference/exportNonInitializedVariablesUMD.errors.txt
@@ -1,15 +1,18 @@
 tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts(2,4): error TS1123: Variable declaration list cannot be empty.
+tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts(3,1): error TS1212: Identifier expected. 'let' is a reserved word in strict mode
 tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts(3,1): error TS2304: Cannot find name 'let'.
 tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts(4,6): error TS1123: Variable declaration list cannot be empty.
 
 
-==== tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts (3 errors) ====
+==== tests/cases/conformance/externalModules/exportNonInitializedVariablesUMD.ts (4 errors) ====
     
     var;
        
 !!! error TS1123: Variable declaration list cannot be empty.
     let;
     ~~~
+!!! error TS1212: Identifier expected. 'let' is a reserved word in strict mode
+    ~~~
 !!! error TS2304: Cannot find name 'let'.
     const;
          
diff --git a/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.errors.txt b/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.errors.txt
new file mode 100644
index 00000000000..94d216724a5
--- /dev/null
+++ b/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.errors.txt
@@ -0,0 +1,23 @@
+tests/cases/conformance/es6/modules/t3.ts(1,17): error TS1212: Identifier expected. 'yield' is a reserved word in strict mode
+
+
+==== tests/cases/conformance/es6/modules/t1.ts (0 errors) ====
+    
+    let set = {
+        set foo(x: number) {
+        }
+    }
+    let get = 10;
+    
+    export { set, get };
+    
+==== tests/cases/conformance/es6/modules/t2.ts (0 errors) ====
+    import * as set from "./t1";
+    
+==== tests/cases/conformance/es6/modules/t3.ts (1 errors) ====
+    import { set as yield } from "./t1";
+                    ~~~~~
+!!! error TS1212: Identifier expected. 'yield' is a reserved word in strict mode
+    
+==== tests/cases/conformance/es6/modules/t4.ts (0 errors) ====
+    import { get } from "./t1";
\ No newline at end of file
diff --git a/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.symbols b/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.symbols
deleted file mode 100644
index f6695a9cf37..00000000000
--- a/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.symbols
+++ /dev/null
@@ -1,30 +0,0 @@
-=== tests/cases/conformance/es6/modules/t1.ts ===
-
-let set = {
->set : Symbol(set, Decl(t1.ts, 1, 3))
-
-    set foo(x: number) {
->foo : Symbol(foo, Decl(t1.ts, 1, 11))
->x : Symbol(x, Decl(t1.ts, 2, 12))
-    }
-}
-let get = 10;
->get : Symbol(get, Decl(t1.ts, 5, 3))
-
-export { set, get };
->set : Symbol(set, Decl(t1.ts, 7, 8))
->get : Symbol(get, Decl(t1.ts, 7, 13))
-
-=== tests/cases/conformance/es6/modules/t2.ts ===
-import * as set from "./t1";
->set : Symbol(set, Decl(t2.ts, 0, 6))
-
-=== tests/cases/conformance/es6/modules/t3.ts ===
-import { set as yield } from "./t1";
->set : Symbol(yield, Decl(t3.ts, 0, 8))
->yield : Symbol(yield, Decl(t3.ts, 0, 8))
-
-=== tests/cases/conformance/es6/modules/t4.ts ===
-import { get } from "./t1";
->get : Symbol(get, Decl(t4.ts, 0, 8))
-
diff --git a/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.types b/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.types
deleted file mode 100644
index a687787c462..00000000000
--- a/tests/baselines/reference/exportsAndImportsWithContextualKeywordNames01.types
+++ /dev/null
@@ -1,32 +0,0 @@
-=== tests/cases/conformance/es6/modules/t1.ts ===
-
-let set = {
->set : { foo: number; }
->{    set foo(x: number) {    }} : { foo: number; }
-
-    set foo(x: number) {
->foo : number
->x : number
-    }
-}
-let get = 10;
->get : number
->10 : number
-
-export { set, get };
->set : { foo: number; }
->get : number
-
-=== tests/cases/conformance/es6/modules/t2.ts ===
-import * as set from "./t1";
->set : typeof set
-
-=== tests/cases/conformance/es6/modules/t3.ts ===
-import { set as yield } from "./t1";
->set : { foo: number; }
->yield : { foo: number; }
-
-=== tests/cases/conformance/es6/modules/t4.ts ===
-import { get } from "./t1";
->get : number
-