diff --git a/export_csv.go b/export_csv.go
index 6a097d6..76604ee 100644
--- a/export_csv.go
+++ b/export_csv.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bufio"
 	"encoding/csv"
 	"fmt"
 	"os"
@@ -22,12 +23,14 @@ func (c *CsvExporter) Convert(filePath string, rows chan []any) error {
 		return err
 	}
 
+	buf := bufio.NewWriterSize(f, 4*1024*1024)
+
 	enc, err := c.Encoding.Encoder()
 	if err != nil {
 		return err
 	}
 
-	w := csv.NewWriter(enc.Writer(f))
+	w := csv.NewWriter(enc.Writer(buf))
 	w.Comma = ';'
 
 	rowNum := 0
@@ -51,6 +54,12 @@ func (c *CsvExporter) Convert(filePath string, rows chan []any) error {
 		return err
 	}
 
+	err = buf.Flush()
+	if err != nil {
+		f.Close()
+		return err
+	}
+
 	err = f.Close()
 	if err != nil {
 		return err
diff --git a/export_csvzip.go b/export_csvzip.go
index 1acbad8..e81d4dc 100644
--- a/export_csvzip.go
+++ b/export_csvzip.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"archive/zip"
+	"bufio"
 	"encoding/csv"
 	"os"
 	"path/filepath"
@@ -22,7 +23,9 @@ func (c *CsvZipExporter) Convert(filePath string, rows chan []any) error {
 		return err
 	}
 
-	z := zip.NewWriter(f)
+	buf := bufio.NewWriterSize(f, 4*1024*1024)
+
+	z := zip.NewWriter(buf)
 
 	zw, err := z.Create(filepath.Base(filePath) + ".csv")
 	if err != nil {
@@ -65,6 +68,12 @@ func (c *CsvZipExporter) Convert(filePath string, rows chan []any) error {
 		return err
 	}
 
+	err = buf.Flush()
+	if err != nil {
+		f.Close()
+		return err
+	}
+
 	err = f.Close()
 	if err != nil {
 		return err