diff --git a/CHANGES.txt b/CHANGES.txt
index 546e3449d3..44cc5dcce5 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -34,6 +34,7 @@ Merged from 5.0:
  * Use estimated compressed size for tables to check if there is enough free space for a compaction (CASSANDRA-21245)
  * Fix failing select on system_views.settings for non-string keys (CASSANDRA-21348)
 Merged from 4.0:
+ * Remove inFlightEcho entry on ECHO_REQ failure (CASSANDRA-21428)
  * Validate snapshot names (CASSANDRA-21389)
 
 
diff --git a/src/java/org/apache/cassandra/gms/Gossiper.java b/src/java/org/apache/cassandra/gms/Gossiper.java
index e35ba861af..979a79a4b2 100644
--- a/src/java/org/apache/cassandra/gms/Gossiper.java
+++ b/src/java/org/apache/cassandra/gms/Gossiper.java
@@ -69,6 +69,7 @@ import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.db.SystemKeyspace;
 import org.apache.cassandra.dht.IPartitioner;
 import org.apache.cassandra.dht.Token;
+import org.apache.cassandra.exceptions.RequestFailure;
 import org.apache.cassandra.locator.InetAddressAndPort;
 import org.apache.cassandra.net.Message;
 import org.apache.cassandra.net.MessagingService;
@@ -659,6 +660,7 @@ public class Gossiper implements IFailureDetectionEventListener, GossiperMBean,
     public void evictFromMembership(InetAddressAndPort endpoint)
     {
         checkProperThreadForStateMutation();
+        inflightEcho.remove(endpoint);
         unreachableEndpoints.remove(endpoint);
         endpointStateMap.remove(endpoint);
         expireTimeEndpointMap.remove(endpoint);
@@ -1201,13 +1203,30 @@ public class Gossiper implements IFailureDetectionEventListener, GossiperMBean,
         {
             Message<NoPayload> echoMessage = Message.out(ECHO_REQ, noPayload);
             logger.trace("Sending ECHO_REQ to {}", addr);
-            RequestCallback echoHandler = msg ->
+            RequestCallback echoHandler = new RequestCallback()
             {
-                runInGossipStageBlocking(() -> {
-                    EndpointState epState = inflightEcho.remove(addr);
-                    if (epState != null)
-                        realMarkAlive(addr, epState);
-                });
+                @Override
+                public void onResponse(Message msg)
+                {
+                    runInGossipStageBlocking(() -> {
+                        EndpointState epState = inflightEcho.remove(addr);
+                        if (epState != null)
+                            realMarkAlive(addr, epState);
+                    });
+                }
+
+                @Override
+                public boolean invokeOnFailure()
+                {
+                    return true;
+                }
+
+                @Override
+                public void onFailure(InetAddressAndPort from, RequestFailure requestFailure)
+                {
+                    logger.trace("ECHO_REQ to {} failed ({})", addr, requestFailure);
+                    inflightEcho.remove(addr);
+                }
             };
             MessagingService.instance().sendWithCallback(echoMessage, addr, echoHandler);
         }