diff --git a/concat_test.go b/concat_test.go
index e223c42..9b127ac 100644
--- a/concat_test.go
+++ b/concat_test.go
@@ -25,7 +25,7 @@ func TestConcat(t *testing.T) {
 			Method: "OPTIONS",
 			Code:   http.StatusOK,
 			ResHeader: map[string]string{
-				"Tus-Extension": "creation,creation-with-upload,concatenation",
+				"Tus-Extension": "creation,creation-with-upload,creation-defer-length,concatenation",
 			},
 		}).Run(handler, t)
 	})
diff --git a/options_test.go b/options_test.go
index 2194035..81b5170 100644
--- a/options_test.go
+++ b/options_test.go
@@ -20,7 +20,7 @@ func TestOptions(t *testing.T) {
 		(&httpTest{
 			Method: "OPTIONS",
 			ResHeader: map[string]string{
-				"Tus-Extension": "creation,creation-with-upload",
+				"Tus-Extension": "creation,creation-with-upload,creation-defer-length",
 				"Tus-Version":   "1.0.0",
 				"Tus-Resumable": "1.0.0",
 				"Tus-Max-Size":  "400",
diff --git a/terminate_test.go b/terminate_test.go
index 098d72c..046141e 100644
--- a/terminate_test.go
+++ b/terminate_test.go
@@ -24,7 +24,7 @@ func TestTerminate(t *testing.T) {
 			Method: "OPTIONS",
 			Code:   http.StatusOK,
 			ResHeader: map[string]string{
-				"Tus-Extension": "creation,creation-with-upload,termination",
+				"Tus-Extension": "creation,creation-with-upload,creation-defer-length,termination",
 			},
 		}).Run(handler, t)
 	})
diff --git a/unrouted_handler.go b/unrouted_handler.go
index 8376ca5..3769bdf 100644
--- a/unrouted_handler.go
+++ b/unrouted_handler.go
@@ -119,7 +119,7 @@ func NewUnroutedHandler(config Config) (*UnroutedHandler, error) {
 	}
 
 	// Only promote extesions using the Tus-Extension header which are implemented
-	extensions := "creation,creation-with-upload"
+	extensions := "creation,creation-with-upload,creation-defer-length"
 	if config.StoreComposer.UsesTerminater {
 		extensions += ",termination"
 	}