diff --git a/packages/compiler-cli/src/transformers/metadata_cache.ts b/packages/compiler-cli/src/transformers/metadata_cache.ts
index fe6033050f..c8846c39bd 100644
--- a/packages/compiler-cli/src/transformers/metadata_cache.ts
+++ b/packages/compiler-cli/src/transformers/metadata_cache.ts
@@ -11,6 +11,7 @@ import * as ts from 'typescript';
 import {MetadataCollector, MetadataValue, ModuleMetadata} from '../metadata/index';
 
 import {MetadataProvider} from './compiler_host';
+import {TS} from './util';
 
 export type ValueTransform = (value: MetadataValue, node: ts.Node) => MetadataValue;
 
@@ -26,7 +27,7 @@ export class MetadataCache implements MetadataProvider {
   private metadataCache = new Map<string, ModuleMetadata|undefined>();
 
   constructor(
-      private collector: MetadataCollector, private strict: boolean,
+      private collector: MetadataCollector, private readonly strict: boolean,
       private transformers: MetadataTransformer[]) {
     for (let transformer of transformers) {
       if (transformer.connect) {
@@ -59,7 +60,8 @@ export class MetadataCache implements MetadataProvider {
       }
     }
 
-    const result = this.collector.getMetadata(sourceFile, this.strict, substitute);
+    const isTsFile = TS.test(sourceFile.fileName);
+    const result = this.collector.getMetadata(sourceFile, this.strict && isTsFile, substitute);
     this.metadataCache.set(sourceFile.fileName, result);
     return result;
   }
diff --git a/packages/compiler-cli/test/ngc_spec.ts b/packages/compiler-cli/test/ngc_spec.ts
index c9add65258..048548cb10 100644
--- a/packages/compiler-cli/test/ngc_spec.ts
+++ b/packages/compiler-cli/test/ngc_spec.ts
@@ -2420,4 +2420,31 @@ describe('ngc transformer command-line', () => {
       expect(moduleSource).toMatch(/inject\(i0\.INJECTOR/);
     });
   });
+
+  it('libraries should not break strictMetadataEmit', () => {
+    // first only generate .d.ts / .js / .metadata.json files
+    writeConfig(`{
+        "extends": "./tsconfig-base.json",
+        "angularCompilerOptions": {
+          "skipTemplateCodegen": true,
+          "strictMetadataEmit": true,
+          "fullTemplateTypeCheck": true
+        },
+        "compilerOptions": {
+          "outDir": "lib"
+        },
+        "files": ["main.ts", "test.d.ts"]
+      }`);
+    write('main.ts', `
+        import {Test} from './test';
+        export const bar = Test.bar;
+    `);
+    write('test.d.ts', `
+        declare export class Test {
+          static bar: string;
+        }
+    `);
+    let exitCode = main(['-p', path.join(basePath, 'tsconfig.json')], errorSpy);
+    expect(exitCode).toEqual(0);
+  });
 });