diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8bc84469c6a..af5d2fddb83 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -8044,7 +8044,7 @@ module ts {
         function checkYieldExpression(node: YieldExpression): Type {
             // Grammar checking
             if (!(node.parserContextFlags & ParserContextFlags.Yield) || isYieldExpressionInClass(node)) {
-                grammarErrorOnFirstToken(node, Diagnostics.A_yield_expression_is_only_allowed_in_a_generator_declaration);
+                grammarErrorOnFirstToken(node, Diagnostics.A_yield_expression_is_only_allowed_in_a_generator_body);
             }
 
             if (node.expression) {
diff --git a/src/compiler/diagnosticInformationMap.generated.ts b/src/compiler/diagnosticInformationMap.generated.ts
index ad3c9b7e796..cd1eafed336 100644
--- a/src/compiler/diagnosticInformationMap.generated.ts
+++ b/src/compiler/diagnosticInformationMap.generated.ts
@@ -120,7 +120,7 @@ module ts {
         Unterminated_template_literal: { code: 1160, category: DiagnosticCategory.Error, key: "Unterminated template literal." },
         Unterminated_regular_expression_literal: { code: 1161, category: DiagnosticCategory.Error, key: "Unterminated regular expression literal." },
         An_object_member_cannot_be_declared_optional: { code: 1162, category: DiagnosticCategory.Error, key: "An object member cannot be declared optional." },
-        A_yield_expression_is_only_allowed_in_a_generator_declaration: { code: 1163, category: DiagnosticCategory.Error, key: "A 'yield' expression is only allowed in a generator declaration." },
+        A_yield_expression_is_only_allowed_in_a_generator_body: { code: 1163, category: DiagnosticCategory.Error, key: "A 'yield' expression is only allowed in a generator body." },
         Computed_property_names_are_not_allowed_in_enums: { code: 1164, category: DiagnosticCategory.Error, key: "Computed property names are not allowed in enums." },
         A_computed_property_name_in_an_ambient_context_must_directly_refer_to_a_built_in_symbol: { code: 1165, category: DiagnosticCategory.Error, key: "A computed property name in an ambient context must directly refer to a built-in symbol." },
         A_computed_property_name_in_a_class_property_declaration_must_directly_refer_to_a_built_in_symbol: { code: 1166, category: DiagnosticCategory.Error, key: "A computed property name in a class property declaration must directly refer to a built-in symbol." },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 0ca1da4bbc8..5ff7d0ce154 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -467,7 +467,7 @@
         "category": "Error",
         "code": 1162
     },
-    "A 'yield' expression is only allowed in a generator declaration.": {
+    "A 'yield' expression is only allowed in a generator body.": {
         "category": "Error",
         "code": 1163
     },
diff --git a/tests/baselines/reference/YieldExpression12_es6.errors.txt b/tests/baselines/reference/YieldExpression12_es6.errors.txt
index 3f007c07b6d..42d447ed5d6 100644
--- a/tests/baselines/reference/YieldExpression12_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression12_es6.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/es6/yieldExpressions/YieldExpression12_es6.ts(3,6): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression12_es6.ts(3,6): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression12_es6.ts (1 errors) ====
@@ -6,6 +6,6 @@ tests/cases/conformance/es6/yieldExpressions/YieldExpression12_es6.ts(3,6): erro
       constructor() {
          yield foo
          ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
       }
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression14_es6.errors.txt b/tests/baselines/reference/YieldExpression14_es6.errors.txt
index 3a47ad2bf39..2e32e7a2388 100644
--- a/tests/baselines/reference/YieldExpression14_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression14_es6.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/es6/yieldExpressions/YieldExpression14_es6.ts(3,6): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression14_es6.ts(3,6): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression14_es6.ts (1 errors) ====
@@ -6,6 +6,6 @@ tests/cases/conformance/es6/yieldExpressions/YieldExpression14_es6.ts(3,6): erro
       foo() {
          yield foo
          ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
       }
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression15_es6.errors.txt b/tests/baselines/reference/YieldExpression15_es6.errors.txt
index ded6fa9aeb8..bb60f6a8f76 100644
--- a/tests/baselines/reference/YieldExpression15_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression15_es6.errors.txt
@@ -1,9 +1,9 @@
-tests/cases/conformance/es6/yieldExpressions/YieldExpression15_es6.ts(2,6): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression15_es6.ts(2,6): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression15_es6.ts (1 errors) ====
     var v = () => {
          yield foo
          ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
       }
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression16_es6.errors.txt b/tests/baselines/reference/YieldExpression16_es6.errors.txt
index ab085ed3cc4..8eb7a7be4cf 100644
--- a/tests/baselines/reference/YieldExpression16_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression16_es6.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/YieldExpression16_es6.ts(1,9): error TS1219: Generators are only available when targeting ECMAScript 6 or higher.
-tests/cases/conformance/es6/yieldExpressions/YieldExpression16_es6.ts(3,5): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression16_es6.ts(3,5): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression16_es6.ts (2 errors) ====
@@ -9,6 +9,6 @@ tests/cases/conformance/es6/yieldExpressions/YieldExpression16_es6.ts(3,5): erro
       function bar() {
         yield foo;
         ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
       }
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression17_es6.errors.txt b/tests/baselines/reference/YieldExpression17_es6.errors.txt
index 59b728ac495..bc262212526 100644
--- a/tests/baselines/reference/YieldExpression17_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression17_es6.errors.txt
@@ -1,6 +1,6 @@
 tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts(1,15): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts(1,15): error TS2378: A 'get' accessor must return a value or consist of a single 'throw' statement.
-tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts(1,23): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts(1,23): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts (3 errors) ====
@@ -10,4 +10,4 @@ tests/cases/conformance/es6/yieldExpressions/YieldExpression17_es6.ts(1,23): err
                   ~~~
 !!! error TS2378: A 'get' accessor must return a value or consist of a single 'throw' statement.
                           ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
\ No newline at end of file
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression18_es6.errors.txt b/tests/baselines/reference/YieldExpression18_es6.errors.txt
index 274592904ed..056fc0e950a 100644
--- a/tests/baselines/reference/YieldExpression18_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression18_es6.errors.txt
@@ -1,8 +1,8 @@
-tests/cases/conformance/es6/yieldExpressions/YieldExpression18_es6.ts(2,1): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression18_es6.ts(2,1): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression18_es6.ts (1 errors) ====
     "use strict";
     yield(foo);
     ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
\ No newline at end of file
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
\ No newline at end of file
diff --git a/tests/baselines/reference/YieldExpression2_es6.errors.txt b/tests/baselines/reference/YieldExpression2_es6.errors.txt
index 280f0b88f93..2d1a7082d53 100644
--- a/tests/baselines/reference/YieldExpression2_es6.errors.txt
+++ b/tests/baselines/reference/YieldExpression2_es6.errors.txt
@@ -1,7 +1,7 @@
-tests/cases/conformance/es6/yieldExpressions/YieldExpression2_es6.ts(1,1): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/YieldExpression2_es6.ts(1,1): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/YieldExpression2_es6.ts (1 errors) ====
     yield foo;
     ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
\ No newline at end of file
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck32.errors.txt b/tests/baselines/reference/generatorTypeCheck32.errors.txt
index 6cd379fd47d..9312371d7eb 100644
--- a/tests/baselines/reference/generatorTypeCheck32.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck32.errors.txt
@@ -1,8 +1,8 @@
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck32.ts(2,29): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck32.ts(2,29): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck32.ts (1 errors) ====
     var s: string;
     var f: () => number = () => yield s;
                                 ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
\ No newline at end of file
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck56.errors.txt b/tests/baselines/reference/generatorTypeCheck56.errors.txt
index c5ab01662bd..99e3b00de41 100644
--- a/tests/baselines/reference/generatorTypeCheck56.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck56.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck56.ts(2,19): error TS9003: 'class' expressions are not currently supported.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck56.ts(3,11): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck56.ts(3,11): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck56.ts (2 errors) ====
@@ -9,7 +9,7 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck56.ts(3,11): erro
 !!! error TS9003: 'class' expressions are not currently supported.
             *[yield 0]() {
               ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
                 yield 0;
             }
         };
diff --git a/tests/baselines/reference/generatorTypeCheck57.errors.txt b/tests/baselines/reference/generatorTypeCheck57.errors.txt
index 9734f445537..c2fe00d7365 100644
--- a/tests/baselines/reference/generatorTypeCheck57.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck57.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck57.ts(2,11): error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck57.ts(3,13): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck57.ts(3,13): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck57.ts (2 errors) ====
@@ -9,6 +9,6 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck57.ts(3,13): erro
 !!! error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
             x = yield 0;
                 ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
         };
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck58.errors.txt b/tests/baselines/reference/generatorTypeCheck58.errors.txt
index f091857cec3..bc8ed769410 100644
--- a/tests/baselines/reference/generatorTypeCheck58.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck58.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck58.ts(2,11): error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck58.ts(3,20): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck58.ts(3,20): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck58.ts (2 errors) ====
@@ -9,6 +9,6 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck58.ts(3,20): erro
 !!! error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
             static x = yield 0;
                        ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
         };
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck59.errors.txt b/tests/baselines/reference/generatorTypeCheck59.errors.txt
index 541fb491af6..3368b79d991 100644
--- a/tests/baselines/reference/generatorTypeCheck59.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck59.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(2,11): error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(3,11): error TS1163: A 'yield' expression is only allowed in a generator declaration.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(3,11): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts (2 errors) ====
@@ -9,7 +9,7 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(3,11): erro
 !!! error TS9004: 'class' declarations are only supported directly inside a module or as a top level declaration.
             @(yield "")
               ~~~~~
-!!! error TS1163: A 'yield' expression is only allowed in a generator declaration.
+!!! error TS1163: A 'yield' expression is only allowed in a generator body.
             m() { }
         };
     }
\ No newline at end of file