diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 470386aa2dd..3b7e787fe4b 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -12361,9 +12361,6 @@ module ts {
             else if ((node.kind === SyntaxKind.ImportDeclaration || node.kind === SyntaxKind.ImportEqualsDeclaration) && flags & NodeFlags.Ambient) {
                 return grammarErrorOnNode(lastDeclare, Diagnostics.A_declare_modifier_cannot_be_used_with_an_import_declaration, "declare");
             }
-            else if (node.kind === SyntaxKind.InterfaceDeclaration && flags & NodeFlags.Ambient) {
-                return grammarErrorOnNode(lastDeclare, Diagnostics.A_declare_modifier_cannot_be_used_with_an_interface_declaration, "declare");
-            }
             else if (node.kind === SyntaxKind.Parameter && (flags & NodeFlags.AccessibilityModifier) && isBindingPattern((<ParameterDeclaration>node).name)) {
                 return grammarErrorOnNode(node, Diagnostics.A_parameter_property_may_not_be_a_binding_pattern);
             }
diff --git a/tests/baselines/reference/declareModifierOnTypeAlias.js b/tests/baselines/reference/declareModifierOnTypeAlias.js
new file mode 100644
index 00000000000..a9bb3c6363c
--- /dev/null
+++ b/tests/baselines/reference/declareModifierOnTypeAlias.js
@@ -0,0 +1,6 @@
+//// [declareModifierOnTypeAlias.ts]
+declare type Foo = string;
+type Bar = number;
+declare type Baz = Bar;
+
+//// [declareModifierOnTypeAlias.js]
diff --git a/tests/baselines/reference/declareModifierOnTypeAlias.symbols b/tests/baselines/reference/declareModifierOnTypeAlias.symbols
new file mode 100644
index 00000000000..32a90fc94da
--- /dev/null
+++ b/tests/baselines/reference/declareModifierOnTypeAlias.symbols
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/declareModifierOnTypeAlias.ts ===
+declare type Foo = string;
+>Foo : Symbol(Foo, Decl(declareModifierOnTypeAlias.ts, 0, 0))
+
+type Bar = number;
+>Bar : Symbol(Bar, Decl(declareModifierOnTypeAlias.ts, 0, 26))
+
+declare type Baz = Bar;
+>Baz : Symbol(Baz, Decl(declareModifierOnTypeAlias.ts, 1, 18))
+>Bar : Symbol(Bar, Decl(declareModifierOnTypeAlias.ts, 0, 26))
+
diff --git a/tests/baselines/reference/declareModifierOnTypeAlias.types b/tests/baselines/reference/declareModifierOnTypeAlias.types
new file mode 100644
index 00000000000..c53616fdff6
--- /dev/null
+++ b/tests/baselines/reference/declareModifierOnTypeAlias.types
@@ -0,0 +1,11 @@
+=== tests/cases/compiler/declareModifierOnTypeAlias.ts ===
+declare type Foo = string;
+>Foo : string
+
+type Bar = number;
+>Bar : number
+
+declare type Baz = Bar;
+>Baz : number
+>Bar : number
+
diff --git a/tests/baselines/reference/parserInterfaceDeclaration5.errors.txt b/tests/baselines/reference/parserInterfaceDeclaration5.errors.txt
deleted file mode 100644
index 2b7ea65e95b..00000000000
--- a/tests/baselines/reference/parserInterfaceDeclaration5.errors.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-tests/cases/conformance/parser/ecmascript5/InterfaceDeclarations/parserInterfaceDeclaration5.ts(1,1): error TS1045: A 'declare' modifier cannot be used with an interface declaration.
-
-
-==== tests/cases/conformance/parser/ecmascript5/InterfaceDeclarations/parserInterfaceDeclaration5.ts (1 errors) ====
-    declare interface I {
-    ~~~~~~~
-!!! error TS1045: A 'declare' modifier cannot be used with an interface declaration.
-    }
\ No newline at end of file
diff --git a/tests/baselines/reference/parserInterfaceDeclaration5.symbols b/tests/baselines/reference/parserInterfaceDeclaration5.symbols
new file mode 100644
index 00000000000..f9b738347ca
--- /dev/null
+++ b/tests/baselines/reference/parserInterfaceDeclaration5.symbols
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/parser/ecmascript5/InterfaceDeclarations/parserInterfaceDeclaration5.ts ===
+declare interface I {
+>I : Symbol(I, Decl(parserInterfaceDeclaration5.ts, 0, 0))
+}
diff --git a/tests/baselines/reference/parserInterfaceDeclaration5.types b/tests/baselines/reference/parserInterfaceDeclaration5.types
new file mode 100644
index 00000000000..c89559fc5c7
--- /dev/null
+++ b/tests/baselines/reference/parserInterfaceDeclaration5.types
@@ -0,0 +1,4 @@
+=== tests/cases/conformance/parser/ecmascript5/InterfaceDeclarations/parserInterfaceDeclaration5.ts ===
+declare interface I {
+>I : I
+}
diff --git a/tests/cases/compiler/declareModifierOnTypeAlias.ts b/tests/cases/compiler/declareModifierOnTypeAlias.ts
new file mode 100644
index 00000000000..0dd23f7eda8
--- /dev/null
+++ b/tests/cases/compiler/declareModifierOnTypeAlias.ts
@@ -0,0 +1,3 @@
+declare type Foo = string;
+type Bar = number;
+declare type Baz = Bar;
\ No newline at end of file