diff --git a/itext/itext.io/itext/io/util/zlib/Deflate.cs b/itext/itext.io/itext/io/util/zlib/Deflate.cs
index af15f4a513..bd64e10e92 100644
--- a/itext/itext.io/itext/io/util/zlib/Deflate.cs
+++ b/itext/itext.io/itext/io/util/zlib/Deflate.cs
@@ -1383,7 +1383,7 @@ internal int deflateInit2(ZStream strm, int level, int method,  int windowBits,
             pending_buf = new byte[lit_bufsize*4];
             pending_buf_size = lit_bufsize*4;
 
-            d_buf = lit_bufsize/2;
+            d_buf = lit_bufsize;
             l_buf = (1+2)*lit_bufsize;
 
             this.level = level;