diff --git a/include/openthread/coap.h b/include/openthread/coap.h
index 6f355e863..bb34b2631 100644
--- a/include/openthread/coap.h
+++ b/include/openthread/coap.h
@@ -487,6 +487,15 @@ ThreadError otCoapAddResource(otInstance *aInstance, otCoapResource *aResource);
  */
 void otCoapRemoveResource(otInstance *aInstance, otCoapResource *aResource);
 
+/**
+ * This function sets the default handler for unhandled CoAP requests.
+ *
+ * @param[in]  aInstance  A pointer to an OpenThread instance.
+ * @param[in]  aHandler   A function pointer that shall be called when an unhandled request arrives.
+ * @param[in]  aContext   A pointer to arbitrary context information. May be NULL if not used.
+ */
+void otCoapSetDefaultHandler(otInstance *aInstance, otCoapRequestHandler aHandler, void *aContext);
+
 /**
  * This function sends a CoAP response from the server.
  *
diff --git a/src/core/api/coap_api.cpp b/src/core/api/coap_api.cpp
index 6358a45da..2a5a81d19 100644
--- a/src/core/api/coap_api.cpp
+++ b/src/core/api/coap_api.cpp
@@ -169,6 +169,11 @@ void otCoapRemoveResource(otInstance *aInstance, otCoapResource *aResource)
     aInstance->mApplicationCoap.RemoveResource(*static_cast<Coap::Resource *>(aResource));
 }
 
+void otCoapSetDefaultHandler(otInstance *aInstance, otCoapRequestHandler aHandler, void *aContext)
+{
+    aInstance->mApplicationCoap.SetDefaultHandler(aHandler, aContext);
+}
+
 ThreadError otCoapSendResponse(otInstance *aInstance, otMessage *aMessage, const otMessageInfo *aMessageInfo)
 {
     return aInstance->mApplicationCoap.SendMessage(
diff --git a/src/core/coap/coap.cpp b/src/core/coap/coap.cpp
index aa593eb17..6c4bce76d 100644
--- a/src/core/coap/coap.cpp
+++ b/src/core/coap/coap.cpp
@@ -59,7 +59,9 @@ Coap::Coap(ThreadNetif &aNetif):
     mRetransmissionTimer(aNetif.GetIp6().mTimerScheduler, &Coap::HandleRetransmissionTimer, this),
     mResources(NULL),
     mInterceptor(NULL),
-    mResponsesQueue(aNetif)
+    mResponsesQueue(aNetif),
+    mDefaultHandler(NULL),
+    mDefaultHandlerContext(NULL)
 {
     mMessageId = static_cast<uint16_t>(otPlatRandomGet());
 }
@@ -136,6 +138,12 @@ exit:
     aResource.mNext = NULL;
 }
 
+void Coap::SetDefaultHandler(otCoapRequestHandler aHandler, void *aContext)
+{
+    mDefaultHandler = aHandler;
+    mDefaultHandlerContext = aContext;
+}
+
 Message *Coap::NewMessage(const Header &aHeader, uint8_t aPriority)
 {
     Message *message = NULL;
@@ -666,6 +674,11 @@ void Coap::ProcessReceivedRequest(Header &aHeader, Message &aMessage, const Ip6:
         }
     }
 
+    if (mDefaultHandler)
+    {
+        mDefaultHandler(mDefaultHandlerContext, &aHeader, &aMessage, &aMessageInfo);
+    }
+
 exit:
 
     if (error != kThreadError_None && response != NULL)
diff --git a/src/core/coap/coap.hpp b/src/core/coap/coap.hpp
index 96add28df..22c4e0a96 100644
--- a/src/core/coap/coap.hpp
+++ b/src/core/coap/coap.hpp
@@ -499,6 +499,13 @@ public:
      */
     void RemoveResource(Resource &aResource);
 
+    /* This function sets the default handler for unhandled CoAP requests.
+     *
+     * @param[in]  aHandler   A function pointer that shall be called when an unhandled request arrives.
+     * @param[in]  aContext   A pointer to arbitrary context information. May be NULL if not used.
+     */
+    void SetDefaultHandler(otCoapRequestHandler aHandler, void *aContext);
+
     /**
      * This method creates a new message with a CoAP header.
      *
@@ -665,6 +672,9 @@ private:
 
     Interceptor    mInterceptor;
     ResponsesQueue mResponsesQueue;
+
+    otCoapRequestHandler mDefaultHandler;
+    void *mDefaultHandlerContext;
 };
 
 }  // namespace Coap