diff --git a/PgBulkInsert/pom.xml b/PgBulkInsert/pom.xml
index 3c8c341..eebfc3d 100644
--- a/PgBulkInsert/pom.xml
+++ b/PgBulkInsert/pom.xml
@@ -53,7 +53,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <postgresql.version>9.4-1206-jdbc42</postgresql.version>
+        <postgresql.version>42.2.2</postgresql.version>
     </properties>
 
     <distributionManagement>
@@ -157,4 +157,4 @@
 
     </dependencies>
 
-</project>
\ No newline at end of file
+</project>
diff --git a/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/PgBulkInsert.java b/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/PgBulkInsert.java
index c5389d1..c538ab9 100644
--- a/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/PgBulkInsert.java
+++ b/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/PgBulkInsert.java
@@ -20,7 +20,6 @@
 import org.postgresql.PGConnection;
 import org.postgresql.copy.CopyIn;
 import org.postgresql.copy.CopyManager;
-import org.postgresql.copy.PGCopyOutputStream;
 
 import java.math.BigDecimal;
 import java.net.Inet4Address;
@@ -33,23 +32,33 @@
 import java.util.stream.Stream;
 
 public abstract class PgBulkInsert<TEntity> implements IPgBulkInsert<TEntity> {
+	
+	private static final int DEFAULT_BUFFER_SIZE = 65536;
 
     private IValueHandlerProvider provider;
 
     private TableDefinition table;
 
     private List<ColumnDefinition<TEntity>> columns;
+    
+    private final int bufferSize;
 
     public PgBulkInsert(String schemaName, String tableName)
     {
-        this(new ValueHandlerProvider(), schemaName, tableName);
+        this(new ValueHandlerProvider(), schemaName, tableName, DEFAULT_BUFFER_SIZE);
+    }
+    
+    public PgBulkInsert(String schemaName, String tableName, int bufferSize)
+    {
+        this(new ValueHandlerProvider(), schemaName, tableName, bufferSize);
     }
 
-    public PgBulkInsert(IValueHandlerProvider provider, String schemaName, String tableName)
+    public PgBulkInsert(IValueHandlerProvider provider, String schemaName, String tableName, int bufferSize)
     {
         this.provider = provider;
         this.table = new TableDefinition(schemaName, tableName);
         this.columns = new ArrayList<>();
+        this.bufferSize = bufferSize;
     }
 
     public void saveAll(PGConnection connection, Stream<TEntity> entities) throws SQLException {
@@ -57,10 +66,10 @@ public void saveAll(PGConnection connection, Stream<TEntity> entities) throws SQ
         CopyManager cpManager = connection.getCopyAPI();
         CopyIn copyIn = cpManager.copyIn(getCopyCommand());
 
-        try (PgBinaryWriter bw = new PgBinaryWriter()) {
+        try (PgBinaryWriter bw = new PgBinaryWriter(bufferSize)) {
 
             // Wrap the CopyOutputStream in our own Writer:
-            bw.open(new PGCopyOutputStream(copyIn));
+            bw.open(copyIn);
 
             // Insert Each Column:
             entities.forEach(entity -> this.saveEntity(bw, entity));
diff --git a/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/pgsql/PgBinaryWriter.java b/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/pgsql/PgBinaryWriter.java
index 4649972..fa4501c 100644
--- a/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/pgsql/PgBinaryWriter.java
+++ b/PgBulkInsert/src/main/java/de/bytefish/pgbulkinsert/pgsql/PgBinaryWriter.java
@@ -8,17 +8,22 @@
 
 import java.io.BufferedOutputStream;
 import java.io.DataOutputStream;
-import java.io.OutputStream;
+
+import org.postgresql.copy.CopyIn;
+import org.postgresql.copy.PGCopyOutputStream;
 
 public class PgBinaryWriter implements AutoCloseable {
 
     private transient DataOutputStream buffer;
+    
+    private final int bufferSize;
 
-    public PgBinaryWriter() {
+    public PgBinaryWriter(int bufferSize) {
+    	this.bufferSize = bufferSize;
     }
 
-    public void open(final OutputStream out) {
-        buffer = new DataOutputStream(new BufferedOutputStream(out));
+    public void open(final CopyIn copyIn) {
+        buffer = new DataOutputStream(new BufferedOutputStream(new PGCopyOutputStream(copyIn, 1), bufferSize));
 
         writeHeader();
     }