diff --git a/modules/core/src/main/java/org/apache/ignite/internal/managers/discovery/DiscoveryMessageFactory.java b/modules/core/src/main/java/org/apache/ignite/internal/managers/discovery/DiscoveryMessageFactory.java
index 1ac4567b31ea0..9e7781c125473 100644
--- a/modules/core/src/main/java/org/apache/ignite/internal/managers/discovery/DiscoveryMessageFactory.java
+++ b/modules/core/src/main/java/org/apache/ignite/internal/managers/discovery/DiscoveryMessageFactory.java
@@ -20,6 +20,7 @@
 import org.apache.ignite.internal.codegen.TcpDiscoveryCheckFailedMessageSerializer;
 import org.apache.ignite.internal.codegen.TcpDiscoveryClientPingRequestSerializer;
 import org.apache.ignite.internal.codegen.TcpDiscoveryClientPingResponseSerializer;
+import org.apache.ignite.internal.codegen.TcpDiscoveryConnectionCheckMessageSerializer;
 import org.apache.ignite.internal.codegen.TcpDiscoveryPingRequestSerializer;
 import org.apache.ignite.internal.codegen.TcpDiscoveryPingResponseSerializer;
 import org.apache.ignite.plugin.extensions.communication.MessageFactory;
@@ -27,6 +28,7 @@
 import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryCheckFailedMessage;
 import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryClientPingRequest;
 import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryClientPingResponse;
+import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryConnectionCheckMessage;
 import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryPingRequest;
 import org.apache.ignite.spi.discovery.tcp.messages.TcpDiscoveryPingResponse;
 
@@ -39,5 +41,6 @@ public class DiscoveryMessageFactory implements MessageFactoryProvider {
         factory.register((short)2, TcpDiscoveryPingResponse::new, new TcpDiscoveryPingResponseSerializer());
         factory.register((short)3, TcpDiscoveryClientPingRequest::new, new TcpDiscoveryClientPingRequestSerializer());
         factory.register((short)4, TcpDiscoveryClientPingResponse::new, new TcpDiscoveryClientPingResponseSerializer());
+        factory.register((short)5, TcpDiscoveryConnectionCheckMessage::new, new TcpDiscoveryConnectionCheckMessageSerializer());
     }
 }
diff --git a/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryAbstractMessage.java b/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryAbstractMessage.java
index c8fea72ec3cfd..d15a642a1db83 100644
--- a/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryAbstractMessage.java
+++ b/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryAbstractMessage.java
@@ -293,8 +293,10 @@ public void addFailedNode(UUID nodeId) {
     /**
      * @param failedNodes Failed nodes.
      */
-    public void failedNodes(@Nullable Set<UUID> failedNodes) {
-        this.failedNodes = failedNodes;
+    public void failedNodes(@Nullable Collection<UUID> failedNodes) {
+        this.failedNodes = failedNodes == null
+            ? null
+            : failedNodes instanceof Set ? (Set<UUID>)failedNodes : new HashSet<>(failedNodes);
     }
 
     /**
diff --git a/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryConnectionCheckMessage.java b/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryConnectionCheckMessage.java
index 21079d0aa12ef..191803bf9b3de 100644
--- a/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryConnectionCheckMessage.java
+++ b/modules/core/src/main/java/org/apache/ignite/spi/discovery/tcp/messages/TcpDiscoveryConnectionCheckMessage.java
@@ -17,11 +17,9 @@
 
 package org.apache.ignite.spi.discovery.tcp.messages;
 
-import java.io.Externalizable;
-import java.io.IOException;
-import java.io.ObjectInput;
-import java.io.ObjectOutput;
+import org.apache.ignite.internal.managers.discovery.DiscoveryMessageFactory;
 import org.apache.ignite.internal.util.typedef.internal.S;
+import org.apache.ignite.plugin.extensions.communication.Message;
 import org.apache.ignite.spi.discovery.tcp.internal.TcpDiscoveryNode;
 
 /**
@@ -29,12 +27,12 @@
  * The difference from {@link TcpDiscoveryStatusCheckMessage} is that this message is sent to the next node
  * which directly replies to the sender without message re-translation to the coordinator.
  */
-public class TcpDiscoveryConnectionCheckMessage extends TcpDiscoveryAbstractMessage implements Externalizable {
+public class TcpDiscoveryConnectionCheckMessage extends TcpDiscoveryAbstractMessage implements Message {
     /** */
     private static final long serialVersionUID = 0L;
 
     /**
-     * Default no-arg constructor for {@link Externalizable} interface.
+     * Default constructor for {@link DiscoveryMessageFactory}.
      */
     public TcpDiscoveryConnectionCheckMessage() {
         // No-op.
@@ -55,13 +53,8 @@ public TcpDiscoveryConnectionCheckMessage(TcpDiscoveryNode creatorNode) {
     }
 
     /** {@inheritDoc} */
-    @Override public void writeExternal(ObjectOutput out) throws IOException {
-        // This method has been left empty intentionally to keep message size at min.
-    }
-
-    /** {@inheritDoc} */
-    @Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
-        // This method has been left empty intentionally to keep message size at min.
+    @Override public short directType() {
+        return 5;
     }
 
     /** {@inheritDoc} */