diff --git a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/dedupe-module-resolve-plugin.ts b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/dedupe-module-resolve-plugin.ts
index 5f89d25845da..2910930dacfe 100644
--- a/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/dedupe-module-resolve-plugin.ts
+++ b/packages/angular_devkit/build_angular/src/angular-cli-files/plugins/dedupe-module-resolve-plugin.ts
@@ -14,11 +14,13 @@ interface NormalModuleFactoryRequest {
   relativePath: string;
   path: string;
   descriptionFileData: {
-    name: string;
-    version: string;
+    name?: string;
+    version?: string;
   };
   descriptionFileRoot: string;
   descriptionFilePath: string;
+  directory?: boolean;
+  file?: boolean;
 }
 
 export interface DedupeModuleResolvePluginOptions {
@@ -45,6 +47,17 @@ export class DedupeModuleResolvePlugin {
           return;
         }
 
+        // When either of these properties is undefined. It typically means it's a link.
+        // In which case we shouldn't try to dedupe it.
+        if (request.file === undefined || request.directory === undefined) {
+          return;
+        }
+
+        // Empty name or versions are no valid primary entrypoints of a library
+        if (!request.descriptionFileData.name || !request.descriptionFileData.version) {
+          return;
+        }
+
         const moduleId = request.descriptionFileData.name + '@' + request.descriptionFileData.version;
         const prevResolvedModule = this.modules.get(moduleId);