diff --git a/tree_test.go b/tree_test.go
index b35ece4..e54b269 100644
--- a/tree_test.go
+++ b/tree_test.go
@@ -22,6 +22,7 @@ func prepare(t *testing.T) Config {
 		"__a",
 		make(map[string]func() string),
 		[]string{"exclude_[0-9]+.bin"},
+		map[string]AppCallback{},
 	)
 
 	err = PopulateTree("./testdata/sunny1", []string{}, config)
@@ -38,6 +39,7 @@ func TestFromNotExistingDirectory(t *testing.T) {
 		"__a",
 		make(map[string]func() string),
 		[]string{},
+		map[string]AppCallback{},
 	)
 
 	_, err := BuildTree("./testing/i_dont_exist", []string{}, config)