diff --git a/client/src/main/java/org/asynchttpclient/netty/NettyResponseFuture.java b/client/src/main/java/org/asynchttpclient/netty/NettyResponseFuture.java
index c5e4a97d0..c29c0f33d 100755
--- a/client/src/main/java/org/asynchttpclient/netty/NettyResponseFuture.java
+++ b/client/src/main/java/org/asynchttpclient/netty/NettyResponseFuture.java
@@ -187,10 +187,10 @@ public boolean cancel(boolean force) {
             return false;
         }
 
-        // cancel could happen before channel was attached
-        if (channel != null) {
-            Channels.setDiscard(channel);
-            Channels.silentlyCloseChannel(channel);
+        final Channel ch = channel; //atomic read, so that it won't end up in TOCTOU
+        if (ch != null) {
+            Channels.setDiscard(ch);
+            Channels.silentlyCloseChannel(ch);
         }
 
         if (ON_THROWABLE_CALLED_FIELD.getAndSet(this, 1) == 0) {