diff --git a/modules/@angular/compiler-cli/src/reflector_host.ts b/modules/@angular/compiler-cli/src/reflector_host.ts
index 44318e7835..29daaf9cdd 100644
--- a/modules/@angular/compiler-cli/src/reflector_host.ts
+++ b/modules/@angular/compiler-cli/src/reflector_host.ts
@@ -184,14 +184,13 @@ export class ReflectorHost implements StaticReflectorHost, ImportGenerator {
       if (this.context.exists(metadataPath)) {
         return this.readMetadata(metadataPath);
       }
+    } else {
+      const sf = this.program.getSourceFile(filePath);
+      if (!sf) {
+        throw new Error(`Source file ${filePath} not present in program.`);
+      }
+      return this.metadataCollector.getMetadata(sf);
     }
-
-    let sf = this.program.getSourceFile(filePath);
-    if (!sf) {
-      throw new Error(`Source file ${filePath} not present in program.`);
-    }
-    const metadata = this.metadataCollector.getMetadata(sf);
-    return metadata;
   }
 
   readMetadata(filePath: string) {
diff --git a/modules/@angular/compiler-cli/test/reflector_host_spec.ts b/modules/@angular/compiler-cli/test/reflector_host_spec.ts
index 4805fe10ba..b7a778423b 100644
--- a/modules/@angular/compiler-cli/test/reflector_host_spec.ts
+++ b/modules/@angular/compiler-cli/test/reflector_host_spec.ts
@@ -92,6 +92,10 @@ describe('reflector_host', () => {
      () => {
          expect(reflectorHost.getMetadataFor('node_modules/@angular/core.d.ts'))
              .toEqual({__symbolic: 'module', version: 1, metadata: {foo: {__symbolic: 'class'}}})});
+
+  it('should be able to read metadata from an otherwise unused .d.ts file ', () => {
+    expect(reflectorHost.getMetadataFor('node_modules/@angular/unused.d.ts')).toBeUndefined();
+  });
 });
 
 const dummyModule = 'export let foo: any[];'
@@ -115,8 +119,8 @@ const FILES: Entry = {
           'core.d.ts': dummyModule,
           'core.metadata.json':
               `{"__symbolic":"module", "version": 1, "metadata": {"foo": {"__symbolic": "class"}}}`,
-          'router-deprecated':
-              {'index.d.ts': dummyModule, 'src': {'providers.d.ts': dummyModule}}
+          'router-deprecated': {'index.d.ts': dummyModule, 'src': {'providers.d.ts': dummyModule}},
+          'unused.d.ts': dummyModule
         }
       }
     }