diff --git a/leshan-server-cluster/src/main/java/org/eclipse/leshan/server/cluster/RedisRegistrationStore.java b/leshan-server-cluster/src/main/java/org/eclipse/leshan/server/cluster/RedisRegistrationStore.java
index 3746a6a3c2..4a8f2943e3 100644
--- a/leshan-server-cluster/src/main/java/org/eclipse/leshan/server/cluster/RedisRegistrationStore.java
+++ b/leshan-server-cluster/src/main/java/org/eclipse/leshan/server/cluster/RedisRegistrationStore.java
@@ -292,37 +292,39 @@ public void remove() {
     @Override
     public Deregistration removeRegistration(String registrationId) {
         try (Jedis j = pool.getResource()) {
+            return removeRegistration(j, registrationId, false);
+        }
+    }
 
-            byte[] regKey = toRegIdKey(registrationId);
-
-            // fetch the client ep by registration ID index
-            byte[] ep = j.get(regKey);
-            if (ep == null) {
-                return null;
-            }
-
-            byte[] data = j.get(toEndpointKey(ep));
-            if (data == null) {
-                return null;
-            }
+    private Deregistration removeRegistration(Jedis j, String registrationId, boolean removeOnlyIfNotAlive) {
+        // fetch the client ep by registration ID index
+        byte[] ep = j.get(toRegIdKey(registrationId));
+        if (ep == null) {
+            return null;
+        }
 
-            Registration r = deserializeReg(data);
-            deleteRegistration(j, r);
-            Collection<Observation> obsRemoved = unsafeRemoveAllObservations(j, r.getId());
-            return new Deregistration(r, obsRemoved);
+        // fetch the client
+        byte[] data = j.get(toEndpointKey(ep));
+        if (data == null) {
+            return null;
         }
-    }
 
-    private void deleteRegistration(Jedis j, Registration r) {
+        Registration r = deserializeReg(data);
+
         byte[] lockValue = null;
         byte[] lockKey = toLockKey(r.getEndpoint());
         try {
             lockValue = RedisLock.acquire(j, lockKey);
 
-            // delete all entries
-            j.del(toRegIdKey(r.getId()));
-            j.del(toEndpointKey(r.getEndpoint()));
-
+            if (!removeOnlyIfNotAlive || !r.isAlive()) {
+                long nbRemoved = j.del(toRegIdKey(r.getId()));
+                if (nbRemoved > 0) {
+                    j.del(toEndpointKey(r.getEndpoint()));
+                    Collection<Observation> obsRemoved = unsafeRemoveAllObservations(j, r.getId());
+                    return new Deregistration(r, obsRemoved);
+                }
+            }
+            return null;
         } finally {
             RedisLock.release(j, lockKey, lockValue);
         }
@@ -669,13 +671,14 @@ public void run() {
                 ScanParams params = new ScanParams().match(REG_EP + "*").count(100);
                 String cursor = "0";
                 do {
-                    // TODO we probably need a lock here
                     ScanResult<byte[]> res = j.scan(cursor.getBytes(), params);
                     for (byte[] key : res.getResult()) {
                         Registration r = deserializeReg(j.get(key));
                         if (!r.isAlive()) {
-                            deleteRegistration(j, r);
-                            expirationListener.registrationExpired(r, new ArrayList<Observation>());
+                            Deregistration dereg = removeRegistration(j, r.getId(), true);
+                            if (dereg != null)
+                                expirationListener.registrationExpired(dereg.getRegistration(),
+                                        dereg.getObservations());
                         }
                     }
                     cursor = res.getStringCursor();