diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index aa268448e..97471af5c 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -395,10 +395,10 @@ exit:
 void Interpreter::ProcessMasterKey(int argc, char *argv[])
 {
     ThreadError error = kThreadError_None;
-    uint8_t keyLength;
 
     if (argc == 0)
     {
+        uint8_t keyLength;
         const uint8_t *key = otGetMasterKey(&keyLength);
 
         for (int i = 0; i < keyLength; i++)
@@ -410,6 +410,7 @@ void Interpreter::ProcessMasterKey(int argc, char *argv[])
     }
     else
     {
+        int8_t keyLength;
         uint8_t key[16];
 
         VerifyOrExit((keyLength = Hex2Bin(argv[0], key, sizeof(key))) >= 0, error = kThreadError_Parse);
diff --git a/src/core/mac/mac.cpp b/src/core/mac/mac.cpp
index 6883827a1..f6236ce41 100644
--- a/src/core/mac/mac.cpp
+++ b/src/core/mac/mac.cpp
@@ -516,6 +516,8 @@ void Mac::TransmitDoneTask(bool aRxPending, ThreadError aError)
             mReceiveTimer.Stop();
         }
 
+    // fall through
+
     case kStateActiveScan:
     case kStateTransmitBeacon:
         SentFrame(aError == kThreadError_None);
diff --git a/src/core/thread/address_resolver.cpp b/src/core/thread/address_resolver.cpp
index 446e8a085..3df28f127 100644
--- a/src/core/thread/address_resolver.cpp
+++ b/src/core/thread/address_resolver.cpp
@@ -542,7 +542,6 @@ void AddressResolver::SendAddressQueryResponse(const ThreadTargetTlv &aTargetTlv
 
     memset(&messageInfo, 0, sizeof(messageInfo));
     memcpy(&messageInfo.GetPeerAddr(), &aDestination, sizeof(messageInfo.GetPeerAddr()));
-    messageInfo.mInterfaceId = messageInfo.mInterfaceId;
     messageInfo.mPeerPort = kCoapUdpPort;
 
     SuccessOrExit(error = mSocket.SendTo(*message, messageInfo));
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index 8087b2957..3ada3f980 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -96,8 +96,7 @@ int MleRouter::AllocateRouterId(void)
 
     // choose available router id at random
     uint8_t freeBit;
-    // freeBit = otPlatRandomGet() % numAvailable;
-    freeBit = 0;
+    freeBit = otPlatRandomGet() % numAvailable;
 
     // allocate router id
     for (int i = 0; i < kMaxRouterId; i++)
diff --git a/src/core/thread/network_data_leader.cpp b/src/core/thread/network_data_leader.cpp
index 9c5350c09..2383e7c42 100644
--- a/src/core/thread/network_data_leader.cpp
+++ b/src/core/thread/network_data_leader.cpp
@@ -873,7 +873,7 @@ ThreadError Leader::AddBorderRouter(PrefixTlv &aPrefix, BorderRouterTlv &aBorder
     PrefixTlv *dstPrefix;
     ContextTlv *dstContext;
     BorderRouterTlv *dstBorderRouter;
-    uint8_t aContextId;
+    int contextId;
 
     if ((dstPrefix = FindPrefix(aPrefix.GetPrefix(), aPrefix.GetPrefixLength())) == NULL)
     {
@@ -890,7 +890,7 @@ ThreadError Leader::AddBorderRouter(PrefixTlv &aPrefix, BorderRouterTlv &aBorder
         {
             dstContext->SetCompress();
         }
-        else if ((aContextId = AllocateContext()) >= 0)
+        else if ((contextId = AllocateContext()) >= 0)
         {
             dstContext = reinterpret_cast<ContextTlv *>(dstPrefix->GetNext());
             Insert(reinterpret_cast<uint8_t *>(dstContext), sizeof(ContextTlv));
@@ -898,7 +898,7 @@ ThreadError Leader::AddBorderRouter(PrefixTlv &aPrefix, BorderRouterTlv &aBorder
             dstContext->Init();
             dstContext->SetStable();
             dstContext->SetCompress();
-            dstContext->SetContextId(aContextId);
+            dstContext->SetContextId(contextId);
             dstContext->SetContextLength(aPrefix.GetPrefixLength());
         }
         else