diff --git a/transport/src/main/java/io/netty/channel/ChannelOutboundBuffer.java b/transport/src/main/java/io/netty/channel/ChannelOutboundBuffer.java
index 48a8c31aa7..393aad8246 100644
--- a/transport/src/main/java/io/netty/channel/ChannelOutboundBuffer.java
+++ b/transport/src/main/java/io/netty/channel/ChannelOutboundBuffer.java
@@ -129,7 +129,7 @@ public final class ChannelOutboundBuffer {
 
         // increment pending bytes after adding message to the unflushed arrays.
         // See https://github.com/netty/netty/issues/1619
-        incrementPendingOutboundBytes(size, true);
+        incrementPendingOutboundBytes(size);
     }
 
     private void addCapacity() {
@@ -164,7 +164,7 @@ public final class ChannelOutboundBuffer {
      * Increment the pending bytes which will be written at some point.
      * This method is thread-safe!
      */
-    void incrementPendingOutboundBytes(int size, boolean fireEvent) {
+    void incrementPendingOutboundBytes(int size) {
         // Cache the channel and check for null to make sure we not produce a NPE in case of the Channel gets
         // recycled while process this method.
         Channel channel = this.channel;
@@ -183,9 +183,7 @@ public final class ChannelOutboundBuffer {
 
         if (newWriteBufferSize > highWaterMark) {
             if (WRITABLE_UPDATER.compareAndSet(this, 1, 0)) {
-                if (fireEvent) {
-                    channel.pipeline().fireChannelWritabilityChanged();
-                }
+                channel.pipeline().fireChannelWritabilityChanged();
             }
         }
     }
@@ -194,7 +192,7 @@ public final class ChannelOutboundBuffer {
      * Decrement the pending bytes which will be written at some point.
      * This method is thread-safe!
      */
-    void decrementPendingOutboundBytes(int size, boolean fireEvent) {
+    void decrementPendingOutboundBytes(int size) {
         // Cache the channel and check for null to make sure we not produce a NPE in case of the Channel gets
         // recycled while process this method.
         Channel channel = this.channel;
@@ -213,9 +211,7 @@ public final class ChannelOutboundBuffer {
 
         if (newWriteBufferSize == 0 || newWriteBufferSize < lowWaterMark) {
             if (WRITABLE_UPDATER.compareAndSet(this, 0, 1)) {
-                if (fireEvent) {
-                    channel.pipeline().fireChannelWritabilityChanged();
-                }
+                channel.pipeline().fireChannelWritabilityChanged();
             }
         }
     }
@@ -316,7 +312,7 @@ public final class ChannelOutboundBuffer {
         safeRelease(msg);
 
         promise.trySuccess();
-        decrementPendingOutboundBytes(size, true);
+        decrementPendingOutboundBytes(size);
 
         return true;
     }
@@ -342,7 +338,7 @@ public final class ChannelOutboundBuffer {
         safeRelease(msg);
 
         safeFail(promise, cause);
-        decrementPendingOutboundBytes(size, true);
+        decrementPendingOutboundBytes(size);
 
         return true;
     }
diff --git a/transport/src/main/java/io/netty/channel/DefaultChannelHandlerContext.java b/transport/src/main/java/io/netty/channel/DefaultChannelHandlerContext.java
index 38eab41398..352aa6426d 100644
--- a/transport/src/main/java/io/netty/channel/DefaultChannelHandlerContext.java
+++ b/transport/src/main/java/io/netty/channel/DefaultChannelHandlerContext.java
@@ -642,7 +642,7 @@ final class DefaultChannelHandlerContext extends DefaultAttributeMap implements
                 ChannelOutboundBuffer buffer = channel.unsafe().outboundBuffer();
                 // Check for null as it may be set to null if the channel is closed already
                 if (buffer != null) {
-                    buffer.incrementPendingOutboundBytes(size, false);
+                    buffer.incrementPendingOutboundBytes(size);
                 }
             }
             executor.execute(WriteTask.newInstance(next, msg, size, flush, promise));
@@ -822,7 +822,7 @@ final class DefaultChannelHandlerContext extends DefaultAttributeMap implements
                     ChannelOutboundBuffer buffer = ctx.channel.unsafe().outboundBuffer();
                     // Check for null as it may be set to null if the channel is closed already
                     if (buffer != null) {
-                        buffer.decrementPendingOutboundBytes(size, false);
+                        buffer.decrementPendingOutboundBytes(size);
                     }
                 }
                 ctx.invokeWrite(msg, promise);
diff --git a/transport/src/test/java/io/netty/channel/ReentrantChannelTest.java b/transport/src/test/java/io/netty/channel/ReentrantChannelTest.java
index 67cd5fbe17..f0bf9bb308 100644
--- a/transport/src/test/java/io/netty/channel/ReentrantChannelTest.java
+++ b/transport/src/test/java/io/netty/channel/ReentrantChannelTest.java
@@ -54,6 +54,8 @@ public class ReentrantChannelTest extends BaseChannelTest {
         clientChannel.close().sync();
 
         assertLog(
+            "WRITABILITY: writable=false\n" +
+            "WRITABILITY: writable=true\n" +
             "WRITE\n" +
             "WRITABILITY: writable=false\n" +
             "FLUSH\n" +
@@ -91,6 +93,9 @@ public class ReentrantChannelTest extends BaseChannelTest {
         clientChannel.close().sync();
 
         assertLog(
+            "WRITABILITY: writable=false\n" +
+            "FLUSH\n" +
+            "WRITABILITY: writable=true\n" +
             "WRITE\n" +
             "WRITABILITY: writable=false\n" +
             "FLUSH\n" +