diff --git a/common/src/main/java/io/netty/util/internal/jzlib/ZStream.java b/common/src/main/java/io/netty/util/internal/jzlib/ZStream.java
index 0d4f2a343a..0aee4233f9 100644
--- a/common/src/main/java/io/netty/util/internal/jzlib/ZStream.java
+++ b/common/src/main/java/io/netty/util/internal/jzlib/ZStream.java
@@ -47,10 +47,15 @@ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 package io.netty.util.internal.jzlib;
 
+import io.netty.logging.InternalLogger;
+import io.netty.logging.InternalLoggerFactory;
 import io.netty.util.internal.jzlib.JZlib.WrapperType;
 
 public final class ZStream {
 
+    private static final InternalLogger logger =
+            InternalLoggerFactory.getInstance(ZStream.class);
+
     public byte[] next_in; // next input byte
     public int next_in_index;
     public int avail_in; // number of bytes available at next_in
@@ -181,10 +186,10 @@ public final class ZStream {
                 next_out.length <= next_out_index ||
                 dstate.pending_buf.length < dstate.pending_out + len ||
                 next_out.length < next_out_index + len) {
-            System.out.println(dstate.pending_buf.length + ", " +
+            logger.debug(dstate.pending_buf.length + ", " +
                     dstate.pending_out + ", " + next_out.length + ", " +
                     next_out_index + ", " + len);
-            System.out.println("avail_out=" + avail_out);
+            logger.debug("avail_out=" + avail_out);
         }
 
         System.arraycopy(dstate.pending_buf, dstate.pending_out, next_out,