diff --git a/helper_test.go b/helper_test.go
new file mode 100644
index 0000000..7f5dcca
--- /dev/null
+++ b/helper_test.go
@@ -0,0 +1,7 @@
+package csv
+
+func must(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
diff --git a/writer_samber_test.go b/writer_samber_test.go
index 3ec545e..2b93413 100644
--- a/writer_samber_test.go
+++ b/writer_samber_test.go
@@ -7,12 +7,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func must(err error) {
-	if err != nil {
-		panic(err)
-	}
-}
-
 func buildTest(forceDoubleQuotes bool, escapeCharEqual bool, escapeCharPlus bool, escapeCharMinus bool, escapeCharAt bool, escapeCharTab bool, escapeCharCR bool) string {
 	var buff strings.Builder
 
diff --git a/writer_stdlib_test.go b/writer_stdlib_test.go
index 8e68a1d..a7f7d9f 100644
--- a/writer_stdlib_test.go
+++ b/writer_stdlib_test.go
@@ -73,7 +73,7 @@ func (e errorWriter) Write(b []byte) (int, error) {
 func TestError(t *testing.T) {
 	b := &bytes.Buffer{}
 	f := NewSafeWriter(b, SafetyOpts{})
-	f.Write([]string{"abc"})
+	must(f.Write([]string{"abc"}))
 	f.Flush()
 	err := f.Error()
 
@@ -82,7 +82,7 @@ func TestError(t *testing.T) {
 	}
 
 	f = NewSafeWriter(errorWriter{}, SafetyOpts{})
-	f.Write([]string{"abc"})
+	must(f.Write([]string{"abc"}))
 	f.Flush()
 	err = f.Error()