diff --git a/packages/compiler-cli/ngcc/src/packages/build_marker.ts b/packages/compiler-cli/ngcc/src/packages/build_marker.ts
index 53288f1bcd..8b23e064d6 100644
--- a/packages/compiler-cli/ngcc/src/packages/build_marker.ts
+++ b/packages/compiler-cli/ngcc/src/packages/build_marker.ts
@@ -22,18 +22,24 @@ export const NGCC_VERSION = '0.0.0-PLACEHOLDER';
  * @param packageJson The parsed contents of the package.json file for the entry-point.
  * @param format The entry-point format property in the package.json to check.
  * @returns true if the entry-point and format have already been processed with this ngcc version.
- * @throws Error if the entry-point has already been processed with a different ngcc
- * version.
+ * @throws Error if the `packageJson` property is not an object.
+ * @throws Error if the entry-point has already been processed with a different ngcc version.
  */
 export function hasBeenProcessed(packageJson: any, format: string): boolean {
-  const compiledVersion =
-      packageJson && packageJson.__modified_by_ngcc__ && packageJson.__modified_by_ngcc__[format];
-  if (compiledVersion && compiledVersion !== NGCC_VERSION) {
+  if (typeof packageJson !== 'object') {
+    throw new Error('`packageJson` parameter is invalid. It parameter must be an object.');
+  }
+  if (!packageJson.__modified_by_ngcc__) {
+    return false;
+  }
+  if (Object.keys(packageJson.__modified_by_ngcc__)
+          .some(property => packageJson.__modified_by_ngcc__[property] !== NGCC_VERSION)) {
     throw new Error(
         'The ngcc compiler has changed since the last ngcc build.\n' +
         'Please completely remove `node_modules` and try again.');
   }
-  return !!compiledVersion;
+
+  return packageJson.__modified_by_ngcc__[format] === NGCC_VERSION;
 }
 
 /**
diff --git a/packages/compiler-cli/ngcc/test/packages/build_marker_spec.ts b/packages/compiler-cli/ngcc/test/packages/build_marker_spec.ts
index 3977b9e1e7..6b13e5e709 100644
--- a/packages/compiler-cli/ngcc/test/packages/build_marker_spec.ts
+++ b/packages/compiler-cli/ngcc/test/packages/build_marker_spec.ts
@@ -10,7 +10,7 @@ import {readFileSync, writeFileSync} from 'fs';
 import * as mockFs from 'mock-fs';
 
 import {AbsoluteFsPath} from '../../../src/ngtsc/path';
-import {checkMarker, writeMarker} from '../../src/packages/build_marker';
+import {checkMarker, hasBeenProcessed, writeMarker} from '../../src/packages/build_marker';
 import {EntryPoint} from '../../src/packages/entry_point';
 
 function createMockFileSystem() {
@@ -150,4 +150,52 @@ describe('Marker files', () => {
               'Please completely remove `node_modules` and try again.');
     });
   });
+
+  describe('hasBeenProcessed', () => {
+    it('should return true if the marker exists for the given format property', () => {
+      expect(
+          hasBeenProcessed({__modified_by_ngcc__: {'fesm2015': '0.0.0-PLACEHOLDER'}}, 'fesm2015'))
+          .toBe(true);
+    });
+    it('should return false if the marker does not exist for the given format property', () => {
+      expect(hasBeenProcessed({__modified_by_ngcc__: {'fesm2015': '0.0.0-PLACEHOLDER'}}, 'module'))
+          .toBe(false);
+    });
+    it('should return false if the no markers exist',
+       () => { expect(hasBeenProcessed({}, 'module')).toBe(false); });
+    it('should throw an Error if the packageJson is not an object', () => {
+      expect(() => hasBeenProcessed(undefined, 'fesm2015'))
+          .toThrowError('`packageJson` parameter is invalid. It parameter must be an object.');
+      expect(
+          () => hasBeenProcessed(
+              '{"__modified_by_ngcc__": {"fesm2015": "0.0.0-PLACEHOLDER"}}', 'fesm2015'))
+          .toThrowError('`packageJson` parameter is invalid. It parameter must be an object.');
+    });
+    it('should throw an Error if the format has been compiled with a different version.', () => {
+      expect(() => hasBeenProcessed({__modified_by_ngcc__: {'fesm2015': '8.0.0'}}, 'fesm2015'))
+          .toThrowError(
+              'The ngcc compiler has changed since the last ngcc build.\n' +
+              'Please completely remove `node_modules` and try again.');
+    });
+    it('should throw an Error if any format has been compiled with a different version.', () => {
+      expect(() => hasBeenProcessed({__modified_by_ngcc__: {'fesm2015': '8.0.0'}}, 'module'))
+          .toThrowError(
+              'The ngcc compiler has changed since the last ngcc build.\n' +
+              'Please completely remove `node_modules` and try again.');
+      expect(
+          () => hasBeenProcessed(
+              {__modified_by_ngcc__: {'module': '0.0.0-PLACEHOLDER', 'fesm2015': '8.0.0'}},
+              'module'))
+          .toThrowError(
+              'The ngcc compiler has changed since the last ngcc build.\n' +
+              'Please completely remove `node_modules` and try again.');
+      expect(
+          () => hasBeenProcessed(
+              {__modified_by_ngcc__: {'module': '0.0.0-PLACEHOLDER', 'fesm2015': '8.0.0'}},
+              'fesm2015'))
+          .toThrowError(
+              'The ngcc compiler has changed since the last ngcc build.\n' +
+              'Please completely remove `node_modules` and try again.');
+    });
+  });
 });