diff --git a/packages/compiler-cli/src/ngtsc/annotations/src/util.ts b/packages/compiler-cli/src/ngtsc/annotations/src/util.ts
index 002a5803d7..a10ff41b54 100644
--- a/packages/compiler-cli/src/ngtsc/annotations/src/util.ts
+++ b/packages/compiler-cli/src/ngtsc/annotations/src/util.ts
@@ -49,22 +49,23 @@ export function getConstructorDependencies(
     let optional = false, self = false, skipSelf = false, host = false;
     let resolved = R3ResolvedDependencyType.Token;
     (param.decorators || []).filter(dec => isCore || isAngularCore(dec)).forEach(dec => {
-      if (dec.name === 'Inject') {
+      const name = isCore || dec.import === null ? dec.name : dec.import !.name;
+      if (name === 'Inject') {
         if (dec.args === null || dec.args.length !== 1) {
           throw new FatalDiagnosticError(
               ErrorCode.DECORATOR_ARITY_WRONG, dec.node,
               `Unexpected number of arguments to @Inject().`);
         }
         tokenExpr = dec.args[0];
-      } else if (dec.name === 'Optional') {
+      } else if (name === 'Optional') {
         optional = true;
-      } else if (dec.name === 'SkipSelf') {
+      } else if (name === 'SkipSelf') {
         skipSelf = true;
-      } else if (dec.name === 'Self') {
+      } else if (name === 'Self') {
         self = true;
-      } else if (dec.name === 'Host') {
+      } else if (name === 'Host') {
         host = true;
-      } else if (dec.name === 'Attribute') {
+      } else if (name === 'Attribute') {
         if (dec.args === null || dec.args.length !== 1) {
           throw new FatalDiagnosticError(
               ErrorCode.DECORATOR_ARITY_WRONG, dec.node,
@@ -74,8 +75,7 @@ export function getConstructorDependencies(
         resolved = R3ResolvedDependencyType.Attribute;
       } else {
         throw new FatalDiagnosticError(
-            ErrorCode.DECORATOR_UNEXPECTED, dec.node,
-            `Unexpected decorator ${dec.name} on parameter.`);
+            ErrorCode.DECORATOR_UNEXPECTED, dec.node, `Unexpected decorator ${name} on parameter.`);
       }
     });
     if (tokenExpr === null) {
diff --git a/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts b/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts
index 9c2c20c57e..1e50aab87d 100644
--- a/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts
+++ b/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts
@@ -160,6 +160,24 @@ describe('ngtsc behavioral tests', () => {
     expect(dtsContents).toContain('static ngInjectableDef: i0.ɵInjectableDef<Service>;');
   });
 
+  it('should compile @Injectable with an @Optional dependency', () => {
+    env.tsconfig();
+    env.write('test.ts', `
+      import {Injectable, Optional as Opt} from '@angular/core';
+
+      @Injectable()
+      class Dep {}
+
+      @Injectable()
+      class Service {
+        constructor(@Opt() dep: Dep) {}
+      }
+    `);
+    env.driveMain();
+    const jsContents = env.getContents('test.js');
+    expect(jsContents).toContain('inject(Dep, 8)');
+  });
+
   it('should compile Components (inline template) without errors', () => {
     env.tsconfig();
     env.write('test.ts', `