diff --git a/testsuite/src/main/java/io/netty/testsuite/transport/AbstractSingleThreadEventLoopTest.java b/testsuite/src/main/java/io/netty/testsuite/transport/AbstractSingleThreadEventLoopTest.java
index fd58a5255bce..80442c92e060 100644
--- a/testsuite/src/main/java/io/netty/testsuite/transport/AbstractSingleThreadEventLoopTest.java
+++ b/testsuite/src/main/java/io/netty/testsuite/transport/AbstractSingleThreadEventLoopTest.java
@@ -20,6 +20,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.util.concurrent.Callable;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.TimeUnit;
@@ -42,7 +43,7 @@
 public abstract class AbstractSingleThreadEventLoopTest {
 
     @Test
-    public void testChannelsRegistered()  {
+    public void testChannelsRegistered() throws Exception {
         EventLoopGroup group = newEventLoopGroup();
         final SingleThreadEventLoop loop = (SingleThreadEventLoop) group.next();
 
@@ -50,28 +51,38 @@ public void testChannelsRegistered()  {
             final Channel ch1 = newChannel();
             final Channel ch2 = newChannel();
 
-            int rc = loop.registeredChannels();
+            int rc = registeredChannels(loop);
             boolean channelCountSupported = rc != -1;
 
             if (channelCountSupported) {
-                assertEquals(0, loop.registeredChannels());
+                assertEquals(0, registeredChannels(loop));
             }
 
             assertTrue(loop.register(ch1).syncUninterruptibly().isSuccess());
             assertTrue(loop.register(ch2).syncUninterruptibly().isSuccess());
             if (channelCountSupported) {
-                assertEquals(2, loop.registeredChannels());
+                assertEquals(2, registeredChannels(loop));
             }
 
             assertTrue(ch1.deregister().syncUninterruptibly().isSuccess());
             if (channelCountSupported) {
-                assertEquals(1, loop.registeredChannels());
+                assertEquals(1, registeredChannels(loop));
             }
         } finally {
             group.shutdownGracefully();
         }
     }
 
+    // Only reliable if run from event loop
+    private static int registeredChannels(final SingleThreadEventLoop loop) throws Exception {
+        return loop.submit(new Callable<Integer>() {
+            @Override
+            public Integer call() {
+                return loop.registeredChannels();
+            }
+        }).get(1, TimeUnit.SECONDS);
+    }
+
     @Test
     @SuppressWarnings("deprecation")
     public void shutdownBeforeStart() throws Exception {
diff --git a/transport/src/test/java/io/netty/channel/nio/NioEventLoopTest.java b/transport/src/test/java/io/netty/channel/nio/NioEventLoopTest.java
index c18759dfb76a..acc8babd81c5 100644
--- a/transport/src/test/java/io/netty/channel/nio/NioEventLoopTest.java
+++ b/transport/src/test/java/io/netty/channel/nio/NioEventLoopTest.java
@@ -23,6 +23,7 @@
 import io.netty.channel.EventLoopTaskQueueFactory;
 import io.netty.channel.SelectStrategy;
 import io.netty.channel.SelectStrategyFactory;
+import io.netty.channel.SingleThreadEventLoop;
 import io.netty.channel.socket.ServerSocketChannel;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.util.IntSupplier;
@@ -42,6 +43,7 @@
 import java.nio.channels.SocketChannel;
 import java.nio.channels.spi.SelectorProvider;
 import java.util.Queue;
+import java.util.concurrent.Callable;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.RejectedExecutionException;
@@ -269,7 +271,7 @@ public int calculateStrategy(IntSupplier selectSupplier, boolean hasTasks) throw
 
     @Ignore
     @Test
-    public void testChannelsRegistered()  {
+    public void testChannelsRegistered() throws Exception {
         NioEventLoopGroup group = new NioEventLoopGroup(1);
         final NioEventLoop loop = (NioEventLoop) group.next();
 
@@ -277,19 +279,29 @@ public void testChannelsRegistered()  {
             final Channel ch1 = new NioServerSocketChannel();
             final Channel ch2 = new NioServerSocketChannel();
 
-            assertEquals(0, loop.registeredChannels());
+            assertEquals(0, registeredChannels(loop));
 
             assertTrue(loop.register(ch1).syncUninterruptibly().isSuccess());
             assertTrue(loop.register(ch2).syncUninterruptibly().isSuccess());
-            assertEquals(2, loop.registeredChannels());
+            assertEquals(2, registeredChannels(loop));
 
             assertTrue(ch1.deregister().syncUninterruptibly().isSuccess());
-            assertEquals(1, loop.registeredChannels());
+            assertEquals(1, registeredChannels(loop));
         } finally {
             group.shutdownGracefully();
         }
     }
 
+    // Only reliable if run from event loop
+    private static int registeredChannels(final SingleThreadEventLoop loop) throws Exception {
+        return loop.submit(new Callable<Integer>() {
+            @Override
+            public Integer call() {
+                return loop.registeredChannels();
+            }
+        }).get(1, TimeUnit.SECONDS);
+    }
+
     @Test
     public void testCustomQueue()  {
         final AtomicBoolean called = new AtomicBoolean();