diff --git a/imagekit/imagecache/celery.py b/imagekit/imagecache/celery.py
index 7e3cf46..3013c66 100644
--- a/imagekit/imagecache/celery.py
+++ b/imagekit/imagecache/celery.py
@@ -30,7 +30,7 @@ class CeleryImageCacheBackend(PessimisticImageCacheBackend):
         try:
             from celery.task import task
         except:
-            raise InvalidImageCacheBackendError("Celery image cache backend requires either the 'celery' library")
+            raise InvalidImageCacheBackendError("Celery image cache backend requires the 'celery' library")
         if not getattr(CeleryImageCacheBackend, '_task', None):
             CeleryImageCacheBackend._task = task(generate)