diff --git a/internal/cnf/parser/nginx/decoder_test.go b/internal/cnf/parser/nginx/decoder_test.go
index b4d40fa..e108071 100644
--- a/internal/cnf/parser/nginx/decoder_test.go
+++ b/internal/cnf/parser/nginx/decoder_test.go
@@ -201,12 +201,12 @@ func TestReceiverAndSyntaxErrors(t *testing.T) {
 	}
 }
 
-var readerError = errors.New("error")
+var errReader = errors.New("error")
 
 type defectiveReader struct{}
 
 func (d defectiveReader) Read(buf []byte) (int, error) {
-	return 0, readerError
+	return 0, errReader
 }
 func TestReadErrors(t *testing.T) {
 
@@ -221,8 +221,8 @@ func TestReadErrors(t *testing.T) {
 		t.Fatalf("expected error")
 	}
 
-	if err.Error() != (&LineError{0, readerError}).Error() {
-		t.Fatalf("expected error <%s>, got <%s>", &LineError{0, readerError}, err)
+	if err.Error() != (&LineError{0, errReader}).Error() {
+		t.Fatalf("expected error <%s>, got <%s>", &LineError{0, errReader}, err)
 	}
 
 }
diff --git a/internal/cnf/parser/nginx/encoder_test.go b/internal/cnf/parser/nginx/encoder_test.go
index c900827..2f50170 100644
--- a/internal/cnf/parser/nginx/encoder_test.go
+++ b/internal/cnf/parser/nginx/encoder_test.go
@@ -167,12 +167,12 @@ func TestDefaultIndent(t *testing.T) {
 	}
 }
 
-var writerError = errors.New("error")
+var errWriter = errors.New("error")
 
 type defectiveWriter struct{}
 
 func (d defectiveWriter) Write(buf []byte) (int, error) {
-	return 0, writerError
+	return 0, errWriter
 }
 
 func TestWriteError(t *testing.T) {
@@ -191,8 +191,8 @@ func TestWriteError(t *testing.T) {
 
 	// encode back to writer
 	encoder := NewEncoder(w)
-	if err := encoder.Encode(receiver); err != writerError {
-		t.Fatalf("expected error <%s>, got <%s>", writerError, err)
+	if err := encoder.Encode(receiver); err != errWriter {
+		t.Fatalf("expected error <%s>, got <%s>", errWriter, err)
 	}
 
 }