diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 12d6d32e1ad..a3af265b359 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5213,7 +5213,7 @@ module ts {
             if (node.declaration) {
                 checkVariableDeclaration(node.declaration);
                 if (node.declaration.type) {
-                    error(node.declaration, Diagnostics.Variable_declarations_of_a_for_statement_cannot_use_a_type_annotation);
+                    error(node.declaration, Diagnostics.The_left_hand_side_of_a_for_in_statement_cannot_use_a_type_annotation);
                 }
             }
 
@@ -5224,7 +5224,7 @@ module ts {
             if (node.variable) {
                 var exprType = checkExpression(node.variable);
                 if (exprType !== anyType && exprType !== stringType) {
-                    error(node.variable, Diagnostics.Variable_declarations_of_a_for_statement_must_be_of_types_string_or_any);
+                    error(node.variable, Diagnostics.The_left_hand_side_of_a_for_in_statement_must_be_of_type_string_or_any);
                 }
                 else {
                     // run check only former check succeeded to avoid cascading errors
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
index b243ef02d1d..c0c2347bb0a 100644
--- a/src/compiler/diagnosticInformationMap.generated.ts
+++ b/src/compiler/diagnosticInformationMap.generated.ts
@@ -114,8 +114,8 @@ module ts {
         The_right_hand_side_of_an_arithmetic_operation_must_be_of_type_any_number_or_an_enum_type: { code: 2112, category: DiagnosticCategory.Error, key: "The right-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type." },
         The_left_hand_side_of_an_arithmetic_operation_must_be_of_type_any_number_or_an_enum_type: { code: 2113, category: DiagnosticCategory.Error, key: "The left-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type." },
         An_arithmetic_operand_must_be_of_type_any_number_or_an_enum_type: { code: 2114, category: DiagnosticCategory.Error, key: "An arithmetic operand must be of type 'any', 'number' or an enum type." },
-        Variable_declarations_of_a_for_statement_cannot_use_a_type_annotation: { code: 2115, category: DiagnosticCategory.Error, key: "Variable declarations of a 'for' statement cannot use a type annotation." },
-        Variable_declarations_of_a_for_statement_must_be_of_types_string_or_any: { code: 2116, category: DiagnosticCategory.Error, key: "Variable declarations of a 'for' statement must be of types 'string' or 'any'." },
+        The_left_hand_side_of_a_for_in_statement_cannot_use_a_type_annotation: { code: 2115, category: DiagnosticCategory.Error, key: "The left-hand side of a 'for...in' statement cannot use a type annotation." },
+        The_left_hand_side_of_a_for_in_statement_must_be_of_type_string_or_any: { code: 2116, category: DiagnosticCategory.Error, key: "The left-hand side of a 'for...in' statement must be of type 'string' or 'any'." },
         The_right_hand_side_of_a_for_in_statement_must_be_of_type_any_an_object_type_or_a_type_parameter: { code: 2117, category: DiagnosticCategory.Error, key: "The right-hand side of a 'for...in' statement must be of type 'any', an object type or a type parameter." },
         The_left_hand_side_of_an_in_expression_must_be_of_types_any_string_or_number: { code: 2118, category: DiagnosticCategory.Error, key: "The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'." },
         The_right_hand_side_of_an_in_expression_must_be_of_type_any_an_object_type_or_a_type_parameter: { code: 2119, category: DiagnosticCategory.Error, key: "The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter" },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index c088fd4eddc..51260ccd6ef 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -448,11 +448,11 @@
         "category": "Error",
         "code": 2114
     },
-    "Variable declarations of a 'for' statement cannot use a type annotation.": {
+    "The left-hand side of a 'for...in' statement cannot use a type annotation.": {
         "category": "Error",
         "code": 2115
     },
-    "Variable declarations of a 'for' statement must be of types 'string' or 'any'.": {
+    "The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.": {
         "category": "Error",
         "code": 2116
     },
diff --git a/tests/baselines/reference/for-inStatementsInvalid.errors.txt b/tests/baselines/reference/for-inStatementsInvalid.errors.txt
index cd47a9297ca..4b4fff8c51c 100644
--- a/tests/baselines/reference/for-inStatementsInvalid.errors.txt
+++ b/tests/baselines/reference/for-inStatementsInvalid.errors.txt
@@ -2,21 +2,21 @@
     var aNumber: number;
     for (aNumber in {}) { }
          ~~~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
     
     var aBoolean: boolean;
     for (aBoolean in {}) { }
          ~~~~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
     
     var aRegExp: RegExp;
     for (aRegExp in {}) { }
          ~~~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
     
     for (var idx : number in {}) { }
              ~~~
-!!! Variable declarations of a 'for' statement cannot use a type annotation.
+!!! The left-hand side of a 'for...in' statement cannot use a type annotation.
     
     function fn(): void { }
     for (var x in fn()) { }
diff --git a/tests/baselines/reference/forIn.errors.txt b/tests/baselines/reference/forIn.errors.txt
index e6d33b50277..51a3b220359 100644
--- a/tests/baselines/reference/forIn.errors.txt
+++ b/tests/baselines/reference/forIn.errors.txt
@@ -2,7 +2,7 @@
     var arr = null;
     for (var i:number in arr) { // error
              ~
-!!! Variable declarations of a 'for' statement cannot use a type annotation.
+!!! The left-hand side of a 'for...in' statement cannot use a type annotation.
         var x1 = arr[i];
         var y1 = arr[i];
     }
diff --git a/tests/baselines/reference/forInStatement4.errors.txt b/tests/baselines/reference/forInStatement4.errors.txt
index 433fa89d535..b228fb93c89 100644
--- a/tests/baselines/reference/forInStatement4.errors.txt
+++ b/tests/baselines/reference/forInStatement4.errors.txt
@@ -2,5 +2,5 @@
     var expr: any;
     for (var a: number in expr) {
              ~
-!!! Variable declarations of a 'for' statement cannot use a type annotation.
+!!! The left-hand side of a 'for...in' statement cannot use a type annotation.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/forInStatement7.errors.txt b/tests/baselines/reference/forInStatement7.errors.txt
index 8e75078d9e8..432fe82237f 100644
--- a/tests/baselines/reference/forInStatement7.errors.txt
+++ b/tests/baselines/reference/forInStatement7.errors.txt
@@ -3,5 +3,5 @@
     var expr: any;
     for (a in expr) {
          ~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/noImplicitAnyForIn.errors.txt b/tests/baselines/reference/noImplicitAnyForIn.errors.txt
index e06c7522cf8..7e4122a8f26 100644
--- a/tests/baselines/reference/noImplicitAnyForIn.errors.txt
+++ b/tests/baselines/reference/noImplicitAnyForIn.errors.txt
@@ -39,4 +39,4 @@
     
     for (n[idx++] in m);
          ~~~~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
\ No newline at end of file
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForInStatement5.errors.txt b/tests/baselines/reference/parserForInStatement5.errors.txt
index 6da9d681a55..d9512576b7b 100644
--- a/tests/baselines/reference/parserForInStatement5.errors.txt
+++ b/tests/baselines/reference/parserForInStatement5.errors.txt
@@ -1,7 +1,7 @@
 ==== tests/cases/conformance/parser/ecmascript5/Statements/parserForInStatement5.ts (2 errors) ====
     for (var a: number in X) {
              ~
-!!! Variable declarations of a 'for' statement cannot use a type annotation.
+!!! The left-hand side of a 'for...in' statement cannot use a type annotation.
                           ~
 !!! Cannot find name 'X'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForInStatement7.errors.txt b/tests/baselines/reference/parserForInStatement7.errors.txt
index f5b5451f8a8..d1c039c751b 100644
--- a/tests/baselines/reference/parserForInStatement7.errors.txt
+++ b/tests/baselines/reference/parserForInStatement7.errors.txt
@@ -3,7 +3,7 @@
                                               ~
 !!! Only a single variable declaration is allowed in a 'for...in' statement.
              ~
-!!! Variable declarations of a 'for' statement cannot use a type annotation.
+!!! The left-hand side of a 'for...in' statement cannot use a type annotation.
                                               ~
 !!! Cannot find name 'X'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForStatement3.errors.txt b/tests/baselines/reference/parserForStatement3.errors.txt
index eab0e8e6805..8af66924fc0 100644
--- a/tests/baselines/reference/parserForStatement3.errors.txt
+++ b/tests/baselines/reference/parserForStatement3.errors.txt
@@ -1,7 +1,7 @@
 ==== tests/cases/conformance/parser/ecmascript5/Statements/parserForStatement3.ts (7 errors) ====
     for(d in _.jh[a]=_.jh[a]||[],b);
         ~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
         ~
 !!! Cannot find name 'd'.
              ~
diff --git a/tests/baselines/reference/parserForStatement4.errors.txt b/tests/baselines/reference/parserForStatement4.errors.txt
index 69dc6388c63..923b05341b5 100644
--- a/tests/baselines/reference/parserForStatement4.errors.txt
+++ b/tests/baselines/reference/parserForStatement4.errors.txt
@@ -3,7 +3,7 @@
          ~
 !!! Cannot find name 'a'.
          ~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
                   ~
 !!! Cannot find name 'b'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForStatement5.errors.txt b/tests/baselines/reference/parserForStatement5.errors.txt
index c3b2ee8d3b7..e1d52c58ab6 100644
--- a/tests/baselines/reference/parserForStatement5.errors.txt
+++ b/tests/baselines/reference/parserForStatement5.errors.txt
@@ -1,7 +1,7 @@
 ==== tests/cases/conformance/parser/ecmascript5/Statements/parserForStatement5.ts (2 errors) ====
     for ({} in b) {
          ~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
                ~
 !!! Cannot find name 'b'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForStatement6.errors.txt b/tests/baselines/reference/parserForStatement6.errors.txt
index 433ce9c43c6..cb758f34359 100644
--- a/tests/baselines/reference/parserForStatement6.errors.txt
+++ b/tests/baselines/reference/parserForStatement6.errors.txt
@@ -3,7 +3,7 @@
          ~~~
 !!! Cannot find name 'foo'.
          ~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
                   ~
 !!! Cannot find name 'b'.
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserForStatement7.errors.txt b/tests/baselines/reference/parserForStatement7.errors.txt
index 19580a0039b..0b1eeba1e05 100644
--- a/tests/baselines/reference/parserForStatement7.errors.txt
+++ b/tests/baselines/reference/parserForStatement7.errors.txt
@@ -1,7 +1,7 @@
 ==== tests/cases/conformance/parser/ecmascript5/Statements/parserForStatement7.ts (3 errors) ====
     for (new foo() in b) {
          ~~~~~~~~~
-!!! Variable declarations of a 'for' statement must be of types 'string' or 'any'.
+!!! The left-hand side of a 'for...in' statement must be of type 'string' or 'any'.
              ~~~
 !!! Cannot find name 'foo'.
                       ~