diff --git a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/FreezeStep.java b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/FreezeStep.java
index 3b67e5bdc17d3..fa5f4c13491d6 100644
--- a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/FreezeStep.java
+++ b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ilm/FreezeStep.java
@@ -5,6 +5,7 @@
  */
 package org.elasticsearch.xpack.core.ilm;
 
+import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.ClusterState;
@@ -26,7 +27,12 @@ public FreezeStep(StepKey key, StepKey nextStepKey, Client client) {
     public void performDuringNoSnapshot(IndexMetaData indexMetaData, ClusterState currentState, Listener listener) {
         getClient().admin().indices().execute(FreezeIndexAction.INSTANCE,
             new FreezeRequest(indexMetaData.getIndex().getName()).masterNodeTimeout(getMasterTimeout(currentState)),
-            ActionListener.wrap(response -> listener.onResponse(true), listener::onFailure));
+            ActionListener.wrap(response -> {
+                if (response.isAcknowledged() == false) {
+                    throw new ElasticsearchException("freeze index request failed to be acknowledged");
+                }
+                listener.onResponse(true);
+            }, listener::onFailure));
     }
 
     @Override
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/FreezeStepTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/FreezeStepTests.java
index 8cd8a2ef0b36d..8dad3cf3a4a81 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/FreezeStepTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/FreezeStepTests.java
@@ -12,6 +12,7 @@
 import org.elasticsearch.action.support.master.AcknowledgedResponse;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.protocol.xpack.frozen.FreezeRequest;
+import org.elasticsearch.protocol.xpack.frozen.FreezeResponse;
 import org.elasticsearch.xpack.core.frozen.action.FreezeIndexAction;
 import org.elasticsearch.xpack.core.ilm.Step.StepKey;
 import org.mockito.Mockito;
@@ -73,7 +74,7 @@ public void testFreeze() {
             assertNotNull(request);
             assertEquals(1, request.indices().length);
             assertEquals(indexMetaData.getIndex().getName(), request.indices()[0]);
-            listener.onResponse(null);
+            listener.onResponse(new FreezeResponse(true, true));
             return null;
         }).when(indicesClient).execute(Mockito.any(), Mockito.any(), Mockito.any());
 
@@ -127,4 +128,32 @@ public void onFailure(Exception e) {
 
         assertThat(exceptionThrown.get(), equalTo(true));
     }
+
+    public void testNotAcknowledged() {
+        IndexMetaData indexMetaData = getIndexMetaData();
+
+        Mockito.doAnswer(invocation -> {
+            @SuppressWarnings("unchecked")
+            ActionListener<AcknowledgedResponse> listener = (ActionListener<AcknowledgedResponse>) invocation.getArguments()[2];
+            listener.onResponse(new FreezeResponse(false, false));
+            return null;
+        }).when(indicesClient).execute(Mockito.any(), Mockito.any(), Mockito.any());
+
+        SetOnce<Boolean> exceptionThrown = new SetOnce<>();
+        FreezeStep step = createRandomInstance();
+        step.performAction(indexMetaData, emptyClusterState(), null, new AsyncActionStep.Listener() {
+            @Override
+            public void onResponse(boolean complete) {
+                throw new AssertionError("Unexpected method call");
+            }
+
+            @Override
+            public void onFailure(Exception e) {
+                assertEquals("freeze index request failed to be acknowledged", e.getMessage());
+                exceptionThrown.set(true);
+            }
+        });
+
+        assertThat(exceptionThrown.get(), equalTo(true));
+    }
 }