diff --git a/fakestorage/bucket.go b/fakestorage/bucket.go
index 4026f1a4a0..93c67e537e 100644
--- a/fakestorage/bucket.go
+++ b/fakestorage/bucket.go
@@ -16,7 +16,8 @@ import (
 	"github.com/gorilla/mux"
 )
 
-var bucketRegexp = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9._-]*[a-zA-Z0-9]$`)
+// https://cloud.google.com/storage/docs/buckets#naming
+var bucketRegexp = regexp.MustCompile(`^[a-z0-9][a-z0-9._-]*[a-z0-9]$`)
 
 // CreateBucket creates a bucket inside the server, so any API calls that
 // require the bucket name will recognize this bucket.
diff --git a/fakestorage/bucket_test.go b/fakestorage/bucket_test.go
index 977b4926f8..edebddf67b 100644
--- a/fakestorage/bucket_test.go
+++ b/fakestorage/bucket_test.go
@@ -252,6 +252,7 @@ func TestServerClientBucketCreateValidation(t *testing.T) {
 		"or spaces",
 		"don't even try",
 		"no/slashes/either",
+		"uppercaseNOTallowed",
 	}
 
 	for _, bucketName := range bucketNames {