diff --git a/packages/compiler-cli/ngcc/src/execution/lock_file.ts b/packages/compiler-cli/ngcc/src/execution/lock_file.ts
index 1bb0ce7273..30efb22f46 100644
--- a/packages/compiler-cli/ngcc/src/execution/lock_file.ts
+++ b/packages/compiler-cli/ngcc/src/execution/lock_file.ts
@@ -75,6 +75,8 @@ export class LockFile {
 
       throw new Error(
           `ngcc is already running at process with id ${pid}.\n` +
+          `If you are running multiple builds in parallel then you should pre-process your node_modules via the command line ngcc tool before starting the builds;\n` +
+          `See https://v9.angular.io/guide/ivy#speeding-up-ngcc-compilation.\n` +
           `(If you are sure no ngcc process is running then you should delete the lockfile at ${this.lockFilePath}.)`);
     }
   }
diff --git a/packages/compiler-cli/ngcc/test/execution/lock_file_spec.ts b/packages/compiler-cli/ngcc/test/execution/lock_file_spec.ts
index 3d09e68082..78da66fae0 100644
--- a/packages/compiler-cli/ngcc/test/execution/lock_file_spec.ts
+++ b/packages/compiler-cli/ngcc/test/execution/lock_file_spec.ts
@@ -183,6 +183,8 @@ runInEachFileSystem(() => {
         expect(() => lockFile.create())
             .toThrowError(
                 `ngcc is already running at process with id 188.\n` +
+                `If you are running multiple builds in parallel then you should pre-process your node_modules via the command line ngcc tool before starting the builds;\n` +
+                `See https://v9.angular.io/guide/ivy#speeding-up-ngcc-compilation.\n` +
                 `(If you are sure no ngcc process is running then you should delete the lockfile at ${lockFile.lockFilePath}.)`);
       });
     });