diff --git a/gcloud-java-storage/src/main/java/com/google/gcloud/spi/StorageRpc.java b/gcloud-java-storage/src/main/java/com/google/gcloud/spi/StorageRpc.java
index 423929adff08..b82acae9cd39 100644
--- a/gcloud-java-storage/src/main/java/com/google/gcloud/spi/StorageRpc.java
+++ b/gcloud-java-storage/src/main/java/com/google/gcloud/spi/StorageRpc.java
@@ -34,8 +34,8 @@ enum Option {
     PREDEFINED_DEFAULT_OBJECT_ACL("predefinedDefaultObjectAcl"),
     IF_METAGENERATION_MATCH("ifMetagenerationMatch"),
     IF_METAGENERATION_NOT_MATCH("ifMetagenerationNotMatch"),
-    IF_GENERATION_NOT_MATCH("ifGenerationMatch"),
-    IF_GENERATION_MATCH("ifGenerationNotMatch"),
+    IF_GENERATION_MATCH("ifGenerationMatch"),
+    IF_GENERATION_NOT_MATCH("ifGenerationNotMatch"),
     IF_SOURCE_METAGENERATION_MATCH("ifSourceMetagenerationMatch"),
     IF_SOURCE_METAGENERATION_NOT_MATCH("ifSourceMetagenerationNotMatch"),
     IF_SOURCE_GENERATION_MATCH("ifSourceGenerationMatch"),