diff --git a/src/main/java/com/vonage/client/voice/AddDtmfListenerRequest.java b/src/main/java/com/vonage/client/voice/AddDtmfListenerRequest.java
index e9f0f3597..97ee4dda5 100644
--- a/src/main/java/com/vonage/client/voice/AddDtmfListenerRequest.java
+++ b/src/main/java/com/vonage/client/voice/AddDtmfListenerRequest.java
@@ -24,7 +24,7 @@
 
 class AddDtmfListenerRequest extends JsonableBaseObject {
     @JsonIgnore final String uuid;
-    @JsonProperty("eventUrl") final Collection<URI> eventUrl;
+    @JsonProperty("event_url") final Collection<URI> eventUrl;
 
     public AddDtmfListenerRequest(String uuid, URI eventUrl) {
         this.uuid = uuid;
diff --git a/src/main/java/com/vonage/client/voice/VoiceClient.java b/src/main/java/com/vonage/client/voice/VoiceClient.java
index b4a8f17e4..09acedce0 100644
--- a/src/main/java/com/vonage/client/voice/VoiceClient.java
+++ b/src/main/java/com/vonage/client/voice/VoiceClient.java
@@ -482,7 +482,7 @@ public TalkResponse stopTalk(String uuid) throws VonageResponseParseException, V
     }
 
     /**
-     * Add a listener for asynchronous DTMF events sent by a caller to an
+     * Register a listener for asynchronous DTMF events sent by a caller to an
      * {@linkplain com.vonage.client.voice.ncco.InputAction} NCCO action, when the
      * {@linkplain com.vonage.client.voice.ncco.InputAction.Builder#mode(InputMode)} is
      * {@link com.vonage.client.voice.ncco.InputMode#ASYNCHRONOUS}.
@@ -502,7 +502,7 @@ public void addDtmfListener(String uuid, String eventUrl) throws VoiceResponseEx
     }
 
     /**
-     * Remove the listener for asynchronous DTMF events sent by a caller to an
+     * Stop receiving updates for asynchronous DTMF events sent by a caller to an
      * {@linkplain com.vonage.client.voice.ncco.InputAction} NCCO, when the
      * {@linkplain com.vonage.client.voice.ncco.InputAction.Builder#mode(InputMode)} is
      * {@link com.vonage.client.voice.ncco.InputMode#ASYNCHRONOUS}. Calling this method
diff --git a/src/test/java/com/vonage/client/voice/VoiceClientTest.java b/src/test/java/com/vonage/client/voice/VoiceClientTest.java
index 214d6f092..e46d30f2e 100644
--- a/src/test/java/com/vonage/client/voice/VoiceClientTest.java
+++ b/src/test/java/com/vonage/client/voice/VoiceClientTest.java
@@ -473,7 +473,7 @@ protected AddDtmfListenerRequest sampleRequest() {
 
             @Override
             protected String sampleRequestBodyString() {
-                return "{\"eventUrl\":[\""+url+"\"]}";
+                return "{\"event_url\":[\""+url+"\"]}";
             }
         }
         .runTests();