diff --git a/packager/src/lib/GlobalTransformCache.js b/packager/src/lib/GlobalTransformCache.js
index b74a1981c..79a169ed2 100644
--- a/packager/src/lib/GlobalTransformCache.js
+++ b/packager/src/lib/GlobalTransformCache.js
@@ -145,6 +145,13 @@ class TransformProfileSet {
   }
 }
 
+class FetchFailedError extends Error {
+  constructor(message) {
+    super();
+    this.message = message;
+  }
+}
+
 /**
  * For some reason the result stored by the server for a key might mismatch what
  * we expect a result to be. So we need to verify carefully the data.
@@ -171,6 +178,8 @@ class GlobalTransformCache {
   _profileSet: TransformProfileSet;
   _store: ?KeyResultStore;
 
+  static FetchFailedError;
+
   /**
    * For using the global cache one needs to have some kind of central key-value
    * store that gets prefilled using keyOf() and the transformed results. The
@@ -214,12 +223,13 @@ class GlobalTransformCache {
   static async _fetchResultFromURI(uri: string): Promise<CachedResult> {
     const response = await fetch(uri, {method: 'GET', timeout: 8000});
     if (response.status !== 200) {
-      throw new Error(`Unexpected HTTP status: ${response.status} ${response.statusText} `);
+      const msg = `Unexpected HTTP status: ${response.status} ${response.statusText} `;
+      throw new FetchFailedError(msg);
     }
     const unvalidatedResult = await response.json();
     const result = validateCachedResult(unvalidatedResult);
     if (result == null) {
-      throw new Error('Server returned invalid result.');
+      throw new FetchFailedError('Server returned invalid result.');
     }
     return result;
   }
@@ -260,4 +270,6 @@ class GlobalTransformCache {
 
 }
 
+GlobalTransformCache.FetchFailedError = FetchFailedError;
+
 module.exports = GlobalTransformCache;