diff --git a/test_runner.go b/test_runner.go
index 9eadebd..ab02db9 100644
--- a/test_runner.go
+++ b/test_runner.go
@@ -22,6 +22,13 @@ type TestcaseDecode struct {
 	err    error
 }
 
+func errorString(err error) string {
+	if err != nil {
+		return err.Error()
+	}
+	return "(no error)"
+}
+
 func RunTestsEncode(t *testing.T, coinType uint32, tests []TestcaseEncode) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -33,13 +40,6 @@ func RunTestsEncode(t *testing.T, coinType uint32, tests []TestcaseEncode) {
 	}
 }
 
-func errorString(err error) string {
-	if err != nil {
-		return err.Error()
-	}
-	return "(no error)"
-}
-
 func RunTestEncode(coinType uint32, tt TestcaseEncode) error {
 	testfun, _ := toBytesMap[coinType]