diff --git a/tests/baselines/reference/generatorTypeCheck39.errors.txt b/tests/baselines/reference/generatorTypeCheck39.errors.txt
index ae24837f712..c9d916f63e9 100644
--- a/tests/baselines/reference/generatorTypeCheck39.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck39.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck39.ts(5,16): error TS1163: A 'yield' expression is only allowed in a generator body.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck39.ts(6,11): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck39.ts(6,11): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck39.ts(7,13): error TS1163: A 'yield' expression is only allowed in a generator body.
 
 
@@ -13,7 +13,7 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck39.ts(7,13): erro
 !!! error TS1163: A 'yield' expression is only allowed in a generator body.
         class C {
               ~
-!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
             x = yield 0;
                 ~~~~~
 !!! error TS1163: A 'yield' expression is only allowed in a generator body.
diff --git a/tests/baselines/reference/generatorTypeCheck59.errors.txt b/tests/baselines/reference/generatorTypeCheck59.errors.txt
index d8179803821..4ba93f10ae0 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(3,11): error TS1163: A 'yield' expression is only allowed in a generator body.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(4,9): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(4,9): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts (2 errors) ====
@@ -10,6 +10,6 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck59.ts(4,9): error
 !!! error TS1163: A 'yield' expression is only allowed in a generator body.
             m() { }
             ~
-!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
         };
     }
\ No newline at end of file
diff --git a/tests/baselines/reference/generatorTypeCheck61.errors.txt b/tests/baselines/reference/generatorTypeCheck61.errors.txt
index b38e96d31ce..2ecfe49973d 100644
--- a/tests/baselines/reference/generatorTypeCheck61.errors.txt
+++ b/tests/baselines/reference/generatorTypeCheck61.errors.txt
@@ -1,5 +1,5 @@
 tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts(2,7): error TS1163: A 'yield' expression is only allowed in a generator body.
-tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts(3,11): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts(3,11): error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
 
 
 ==== tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts (2 errors) ====
@@ -9,5 +9,5 @@ tests/cases/conformance/es6/yieldExpressions/generatorTypeCheck61.ts(3,11): erro
 !!! error TS1163: A 'yield' expression is only allowed in a generator body.
         class C {};
               ~
-!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.
+!!! error TS1219: Experimental support for decorators is a feature that is subject to change in a future release. Set 'experimentalDecorators' to remove this warning.
     }
\ No newline at end of file
diff --git a/tests/cases/compiler/jsFileCompilationDecoratorSyntax.ts b/tests/cases/compiler/jsFileCompilationDecoratorSyntax.ts
index ece41012dfe..6627fb5dca0 100644
--- a/tests/cases/compiler/jsFileCompilationDecoratorSyntax.ts
+++ b/tests/cases/compiler/jsFileCompilationDecoratorSyntax.ts
@@ -1,4 +1,5 @@
 // @allowJs: true
 // @noEmit: true
+// @experimentalDecorators: true
 // @filename: a.js
-@internal class C { }
\ No newline at end of file
+@internal class C { }
diff --git a/tests/cases/fourslash/getJavaScriptSemanticDiagnostics21.ts b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics21.ts
index 04dae8b592b..8a7120acbb3 100644
--- a/tests/cases/fourslash/getJavaScriptSemanticDiagnostics21.ts
+++ b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics21.ts
@@ -1,6 +1,7 @@
 /// <reference path="fourslash.ts" />
 
 // @allowJs: true
+// @experimentalDecorators: true
 // @Filename: a.js
 //// @internal class C {}