diff --git a/examples/drivers/windows/otApi/otApi.cpp b/examples/drivers/windows/otApi/otApi.cpp
index 978ecd671..fa176116a 100644
--- a/examples/drivers/windows/otApi/otApi.cpp
+++ b/examples/drivers/windows/otApi/otApi.cpp
@@ -1335,6 +1335,7 @@ otThreadDiscover(
     _In_ otInstance *aInstance, 
     uint32_t aScanChannels, 
     uint16_t aPanid,
+    bool aJoiner,
     otHandleActiveScanResult aCallback,
     void *aCallbackContext
     )
@@ -1346,7 +1347,7 @@ otThreadDiscover(
         aInstance->InterfaceGuid, aCallback, aCallbackContext
         );
 
-    PackedBuffer3<GUID,uint32_t,uint16_t> Buffer(aInstance->InterfaceGuid, aScanChannels, aPanid);
+    PackedBuffer4<GUID,uint32_t,uint16_t, bool> Buffer(aInstance->InterfaceGuid, aScanChannels, aPanid, aJoiner);
     return DwordToThreadError(SendIOCTL(aInstance->ApiHandle, IOCTL_OTLWF_OT_DISCOVER, &Buffer, sizeof(Buffer), nullptr, 0));
 }
 
diff --git a/examples/drivers/windows/otLwf/iocontrol.c b/examples/drivers/windows/otLwf/iocontrol.c
index 82725c68c..9b7c9c6fa 100644
--- a/examples/drivers/windows/otLwf/iocontrol.c
+++ b/examples/drivers/windows/otLwf/iocontrol.c
@@ -904,15 +904,17 @@ otLwfIoCtl_otDiscover(
 {
     NTSTATUS status = STATUS_INVALID_PARAMETER;
 
-    if (InBufferLength >= sizeof(uint32_t) + sizeof(uint16_t))
+    if (InBufferLength >= sizeof(uint32_t) + sizeof(uint16_t) + sizeof(bool))
     {
         uint32_t aScanChannels = *(uint32_t*)InBuffer;
         uint16_t aPanid = *(uint16_t*)(InBuffer + sizeof(uint32_t));
+        bool aJoiner = *(bool*)(InBuffer + sizeof(uint32_t) + sizeof(uint16_t));
         status = ThreadErrorToNtstatus(
             otThreadDiscover(
                 pFilter->otCtx, 
                 aScanChannels, 
                 aPanid,
+                aJoiner,
                 otLwfDiscoverCallback,
                 pFilter)
             );
diff --git a/include/openthread/thread.h b/include/openthread/thread.h
index ba58d1979..cb94a1a91 100644
--- a/include/openthread/thread.h
+++ b/include/openthread/thread.h
@@ -115,6 +115,7 @@ OTAPI bool OTCALL otThreadIsSingleton(otInstance *aInstance);
  * @param[in]  aInstance         A pointer to an OpenThread instance.
  * @param[in]  aScanChannels     A bit vector indicating which channels to scan (e.g. OT_CHANNEL_11_MASK).
  * @param[in]  aPanId            The PAN ID filter (set to Broadcast PAN to disable filter).
+ * @param[in]  aJoiner           Value of the Joiner Flag in the Discovery Request TLV.
  * @param[in]  aCallback         A pointer to a function called on receiving an MLE Discovery Response or scan completes.
  * @param[in]  aCallbackContext  A pointer to application-specific context.
  *
@@ -122,7 +123,7 @@ OTAPI bool OTCALL otThreadIsSingleton(otInstance *aInstance);
  * @retval kThreadError_Busy  Already performing an Thread Discovery.
  *
  */
-OTAPI ThreadError OTCALL otThreadDiscover(otInstance *aInstance, uint32_t aScanChannels, uint16_t aPanid,
+OTAPI ThreadError OTCALL otThreadDiscover(otInstance *aInstance, uint32_t aScanChannels, uint16_t aPanid, bool aJoiner,
                                           otHandleActiveScanResult aCallback, void *aCallbackContext);
 
 /**
diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index b14fd90f1..aa4c863fe 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -747,7 +747,7 @@ void Interpreter::ProcessDiscover(int argc, char *argv[])
         scanChannels = 1 << value;
     }
 
-    SuccessOrExit(error = otThreadDiscover(mInstance, scanChannels, OT_PANID_BROADCAST,
+    SuccessOrExit(error = otThreadDiscover(mInstance, scanChannels, OT_PANID_BROADCAST, false,
                                            &Interpreter::s_HandleActiveScanResult, this));
     sServer->OutputFormat("| J | Network Name     | Extended PAN     | PAN  | MAC Address      | Ch | dBm | LQI |\r\n");
     sServer->OutputFormat("+---+------------------+------------------+------+------------------+----+-----+-----+\r\n");
diff --git a/src/core/api/thread_api.cpp b/src/core/api/thread_api.cpp
index 3b403fd36..931051186 100644
--- a/src/core/api/thread_api.cpp
+++ b/src/core/api/thread_api.cpp
@@ -678,10 +678,10 @@ bool otThreadIsSingleton(otInstance *aInstance)
     return aInstance->mThreadNetif.GetMle().IsSingleton();
 }
 
-ThreadError otThreadDiscover(otInstance *aInstance, uint32_t aScanChannels, uint16_t aPanId,
+ThreadError otThreadDiscover(otInstance *aInstance, uint32_t aScanChannels, uint16_t aPanId, bool aJoiner,
                              otHandleActiveScanResult aCallback, void *aCallbackContext)
 {
-    return aInstance->mThreadNetif.GetMle().Discover(aScanChannels, aPanId, false, aCallback, aCallbackContext);
+    return aInstance->mThreadNetif.GetMle().Discover(aScanChannels, aPanId, aJoiner, aCallback, aCallbackContext);
 }
 
 bool otThreadIsDiscoverInProgress(otInstance *aInstance)