diff --git a/examples/drivers/windows/otApi/otApi.cpp b/examples/drivers/windows/otApi/otApi.cpp
index 2f096c1cb..b19db0f6c 100644
--- a/examples/drivers/windows/otApi/otApi.cpp
+++ b/examples/drivers/windows/otApi/otApi.cpp
@@ -2795,17 +2795,11 @@ OTAPI
 otError
 OTCALL
 otThreadBecomeChild(
-    _In_ otInstance *aInstance, 
-    otMleAttachFilter aFilter
+    _In_ otInstance *aInstance
     )
 {
     if (aInstance == nullptr) return OT_ERROR_INVALID_ARGS;
-
-    uint8_t Role = kDeviceRoleDetached;
-    uint8_t Filter = (uint8_t)aFilter;
-
-    PackedBuffer3<GUID,uint8_t,uint8_t> Buffer(aInstance->InterfaceGuid, Role, Filter);
-    return DwordToThreadError(SendIOCTL(aInstance->ApiHandle, IOCTL_OTLWF_OT_DEVICE_ROLE, &Buffer, sizeof(Buffer), nullptr, 0));
+    return DwordToThreadError(SetIOCTL(aInstance, IOCTL_OTLWF_OT_DEVICE_ROLE, (uint8_t)kDeviceRoleChild));
 }
 
 OTAPI
diff --git a/examples/drivers/windows/otLwf/iocontrol.c b/examples/drivers/windows/otLwf/iocontrol.c
index 93ccc5844..3c6e121d3 100644
--- a/examples/drivers/windows/otLwf/iocontrol.c
+++ b/examples/drivers/windows/otLwf/iocontrol.c
@@ -3773,12 +3773,9 @@ otLwfIoCtl_otDeviceRole(
         }
         else if (role == kDeviceRoleChild)
         {
-            if (InBufferLength >= sizeof(uint8_t))
-            {
-                status = ThreadErrorToNtstatus(
-                            otThreadBecomeChild(pFilter->otCtx, *(uint8_t*)InBuffer)
-                            );
-            }
+            status = ThreadErrorToNtstatus(
+                        otThreadBecomeChild(pFilter->otCtx)
+                        );
         }
         else if (role == kDeviceRoleDetached)
         {
diff --git a/examples/drivers/windows/otNodeApi/otNodeApi.cpp b/examples/drivers/windows/otNodeApi/otNodeApi.cpp
index 24f5c745c..56df95b48 100644
--- a/examples/drivers/windows/otNodeApi/otNodeApi.cpp
+++ b/examples/drivers/windows/otNodeApi/otNodeApi.cpp
@@ -1406,7 +1406,7 @@ OTNODEAPI int32_t OTCALL otNodeSetState(otNode* aNode, const char *aState)
     }
     else if (strcmp(aState, "child") == 0)
     {
-        error = otThreadBecomeChild(aNode->mInstance, kMleAttachAnyPartition);
+        error = otThreadBecomeChild(aNode->mInstance);
     }
     else if (strcmp(aState, "router") == 0)
     {
diff --git a/include/openthread/thread.h b/include/openthread/thread.h
index 58175fbb8..2757a87fe 100644
--- a/include/openthread/thread.h
+++ b/include/openthread/thread.h
@@ -359,12 +359,11 @@ OTAPI otError OTCALL otThreadBecomeDetached(otInstance *aInstance);
  * Attempt to reattach as a child.
  *
  * @param[in]  aInstance A pointer to an OpenThread instance.
- * @param[in]  aFilter   Identifies whether to join any, same, or better partition.
  *
  * @retval OT_ERROR_NONE           Successfully begin attempt to become a child.
  * @retval OT_ERROR_INVALID_STATE  Thread is disabled.
  */
-OTAPI otError OTCALL otThreadBecomeChild(otInstance *aInstance, otMleAttachFilter aFilter);
+OTAPI otError OTCALL otThreadBecomeChild(otInstance *aInstance);
 
 /**
  * This function gets the next neighbor information. It is used to go through the entries of
diff --git a/include/openthread/types.h b/include/openthread/types.h
index a11a25b9b..939ea8043 100644
--- a/include/openthread/types.h
+++ b/include/openthread/types.h
@@ -755,17 +755,6 @@ typedef enum otRoutePreference
     OT_ROUTE_PREFERENCE_HIGH = 1,   ///< High route preference.
 } otRoutePreference;
 
-/**
- * Represents any restrictions on the attach process.
- */
-typedef enum otMleAttachFilter
-{
-    kMleAttachAnyPartition    = 0,  ///< Attach to any Thread partition.
-    kMleAttachSamePartition1  = 1,  ///< Attach to the same Thread partition (attempt 1).
-    kMleAttachSamePartition2  = 2,  ///< Attach to the same Thread partition (attempt 2).
-    kMleAttachBetterPartition = 3,  ///< Attach to a better (i.e. higher weight/partition id) Thread partition.
-} otMleAttachFilter;
-
 /**
  * This structure represents a whitelist entry.
  *
diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index 4e9d48d9a..412cb9492 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -2451,7 +2451,7 @@ void Interpreter::ProcessState(int argc, char *argv[])
         }
         else if (strcmp(argv[0], "child") == 0)
         {
-            SuccessOrExit(error = otThreadBecomeChild(mInstance, kMleAttachSamePartition1));
+            SuccessOrExit(error = otThreadBecomeChild(mInstance));
         }
 
 #if OPENTHREAD_FTD
diff --git a/src/core/api/thread_api.cpp b/src/core/api/thread_api.cpp
index bd5878f51..3fc119995 100644
--- a/src/core/api/thread_api.cpp
+++ b/src/core/api/thread_api.cpp
@@ -240,9 +240,9 @@ otError otThreadBecomeDetached(otInstance *aInstance)
     return aInstance->mThreadNetif.GetMle().BecomeDetached();
 }
 
-otError otThreadBecomeChild(otInstance *aInstance, otMleAttachFilter aFilter)
+otError otThreadBecomeChild(otInstance *aInstance)
 {
-    return aInstance->mThreadNetif.GetMle().BecomeChild(aFilter);
+    return aInstance->mThreadNetif.GetMle().BecomeChild(Mle::kAttachAny);
 }
 
 otError otThreadGetNextNeighborInfo(otInstance *aInstance, otNeighborInfoIterator *aIterator, otNeighborInfo *aInfo)
diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index edf638461..da6834035 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -81,7 +81,7 @@ Mle::Mle(ThreadNetif &aThreadNetif) :
     mLastPartitionRouterIdSequence(0),
     mLastPartitionId(0),
     mParentLeaderCost(0),
-    mParentRequestMode(kMleAttachAnyPartition),
+    mParentRequestMode(kAttachAny),
     mParentPriority(0),
     mParentLinkQuality3(0),
     mParentLinkQuality2(0),
@@ -232,13 +232,13 @@ otError Mle::Start(bool aEnableReattach, bool aAnnounceAttach)
 
     if (aAnnounceAttach || (GetRloc16() == Mac::kShortAddrInvalid))
     {
-        BecomeChild(kMleAttachAnyPartition);
+        BecomeChild(kAttachAny);
     }
     else if (IsActiveRouter(GetRloc16()))
     {
         if (mNetif.GetMle().BecomeRouter(ThreadStatusTlv::kTooFewRouters) != OT_ERROR_NONE)
         {
-            BecomeChild(kMleAttachAnyPartition);
+            BecomeChild(kAttachAny);
         }
     }
     else
@@ -480,14 +480,14 @@ otError Mle::BecomeDetached(void)
 
     SetStateDetached();
     SetRloc16(Mac::kShortAddrInvalid);
-    BecomeChild(kMleAttachAnyPartition);
+    BecomeChild(kAttachAny);
 
 exit:
     otLogFuncExitErr(error);
     return error;
 }
 
-otError Mle::BecomeChild(otMleAttachFilter aFilter)
+otError Mle::BecomeChild(AttachMode aMode)
 {
     otError error = OT_ERROR_NONE;
 
@@ -510,9 +510,9 @@ otError Mle::BecomeChild(otMleAttachFilter aFilter)
 
     ResetParentCandidate();
     mParentRequestState = kParentRequestStart;
-    mParentRequestMode = aFilter;
+    mParentRequestMode = aMode;
 
-    if (aFilter != kMleAttachBetterPartition)
+    if (aMode != kAttachBetter)
     {
         memset(&mParent, 0, sizeof(mParent));
 
@@ -522,7 +522,7 @@ otError Mle::BecomeChild(otMleAttachFilter aFilter)
         }
     }
 
-    if (aFilter == kMleAttachAnyPartition)
+    if (aMode == kAttachAny)
     {
         mParent.SetState(Neighbor::kStateInvalid);
         mLastPartitionId = mNetif.GetMle().GetPreviousPartitionId();
@@ -1292,7 +1292,7 @@ void Mle::HandleParentRequestTimer(void)
 
     case kParentSynchronize:
         mParentRequestState = kParentIdle;
-        BecomeChild(kMleAttachAnyPartition);
+        BecomeChild(kAttachAny);
         break;
 
     case kParentRequestStart:
@@ -1355,7 +1355,7 @@ void Mle::HandleParentRequestTimer(void)
             {
                 switch (mParentRequestMode)
                 {
-                case kMleAttachAnyPartition:
+                case kAttachAny:
                     if (mPreviousPanId != Mac::kPanIdBroadcast)
                     {
                         mNetif.GetMac().SetChannel(mPreviousChannel);
@@ -1376,17 +1376,17 @@ void Mle::HandleParentRequestTimer(void)
 
                     break;
 
-                case kMleAttachSamePartition1:
+                case kAttachSame1:
                     mParentRequestState = kParentIdle;
-                    BecomeChild(kMleAttachSamePartition2);
+                    BecomeChild(kAttachSame2);
                     break;
 
-                case kMleAttachSamePartition2:
+                case kAttachSame2:
                     mParentRequestState = kParentIdle;
-                    BecomeChild(kMleAttachAnyPartition);
+                    BecomeChild(kAttachAny);
                     break;
 
-                case kMleAttachBetterPartition:
+                case kAttachBetter:
                     mParentRequestState = kParentIdle;
 
                     if (mDeviceState == kDeviceStateChild)
@@ -1406,7 +1406,7 @@ void Mle::HandleParentRequestTimer(void)
         mParentRequestState = kParentIdle;
         ResetParentCandidate();
 
-        if ((mParentRequestMode == kMleAttachBetterPartition) || (mDeviceState == kDeviceStateRouter) ||
+        if ((mParentRequestMode == kAttachBetter) || (mDeviceState == kDeviceStateRouter) ||
             (mDeviceState == kDeviceStateLeader))
         {
             if (mDeviceState == kDeviceStateChild)
@@ -1494,8 +1494,8 @@ otError Mle::SendParentRequest(void)
     case kParentRequestRouter:
         scanMask = ScanMaskTlv::kRouterFlag;
 
-        if (mParentRequestMode == kMleAttachSamePartition1 ||
-            mParentRequestMode == kMleAttachSamePartition2)
+        if (mParentRequestMode == kAttachSame1 ||
+            mParentRequestMode == kAttachSame2)
         {
             scanMask |= ScanMaskTlv::kEndDeviceFlag;
         }
@@ -2599,18 +2599,18 @@ otError Mle::HandleParentResponse(const Message &aMessage, const Ip6::MessageInf
 
         switch (mParentRequestMode)
         {
-        case kMleAttachAnyPartition:
+        case kAttachAny:
             VerifyOrExit(leaderData.GetPartitionId() != mLeaderData.GetPartitionId() || diff > 0);
             break;
 
-        case kMleAttachSamePartition1:
-        case kMleAttachSamePartition2:
+        case kAttachSame1:
+        case kAttachSame2:
             VerifyOrExit(leaderData.GetPartitionId() == mLeaderData.GetPartitionId());
             VerifyOrExit(diff > 0 ||
                          (diff == 0 && mNetif.GetMle().GetLeaderAge() < mNetif.GetMle().GetNetworkIdTimeout()));
             break;
 
-        case kMleAttachBetterPartition:
+        case kAttachBetter:
             VerifyOrExit(leaderData.GetPartitionId() != mLeaderData.GetPartitionId());
             VerifyOrExit(mNetif.GetMle().ComparePartitions(connectivity.GetActiveRouters() <= 1, leaderData,
                                                            mNetif.GetMle().IsSingleton(), mLeaderData) > 0);
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index 32b4ab6b8..12e4cdb4c 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -103,6 +103,18 @@ enum DeviceState
     kDeviceStateLeader   = 4,   ///< Thread interface participating as a Leader.
 };
 
+/**
+ * MLE Attach modes
+ *
+ */
+enum AttachMode
+{
+    kAttachAny    = 0,  ///< Attach to any Thread partition.
+    kAttachSame1  = 1,  ///< Attach to the same Thread partition (attempt 1).
+    kAttachSame2  = 2,  ///< Attach to the same Thread partition (attempt 2).
+    kAttachBetter = 3,  ///< Attach to a better (i.e. higher weight/partition id) Thread partition.
+};
+
 /**
  * This enumeration represents the allocation of the ALOC Space
  *
@@ -590,14 +602,14 @@ public:
     /**
      * This method causes the Thread interface to attempt an MLE attach.
      *
-     * @param[in]  aFilter  Indicates what partitions to attach to.
+     * @param[in]  aMode  Indicates what partitions to attach to.
      *
      * @retval OT_ERROR_NONE           Successfully began the attach process.
      * @retval OT_ERROR_INVALID_STATE  MLE is Disabled.
      * @retval OT_ERROR_BUSY           An attach process is in progress.
      *
      */
-    otError BecomeChild(otMleAttachFilter aFilter);
+    otError BecomeChild(AttachMode aMode);
 
     /**
      * This method indicates whether or not the Thread device is attached to a Thread network.
@@ -1400,7 +1412,7 @@ private:
         uint8_t mChallenge[ChallengeTlv::kMaxSize];
     } mParentRequest;
 
-    otMleAttachFilter mParentRequestMode;
+    AttachMode mParentRequestMode;
     int8_t mParentPriority;
     uint8_t mParentLinkQuality3;
     uint8_t mParentLinkQuality2;
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index 05c4c8fe6..3a9438c69 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -349,7 +349,7 @@ otError MleRouter::HandleDetachStart(void)
     return error;
 }
 
-otError MleRouter::HandleChildStart(otMleAttachFilter aFilter)
+otError MleRouter::HandleChildStart(AttachMode aMode)
 {
     otError error = OT_ERROR_NONE;
     mRouterIdSequenceLastUpdated = Timer::GetNow();
@@ -367,10 +367,10 @@ otError MleRouter::HandleChildStart(otMleAttachFilter aFilter)
 
     VerifyOrExit(IsRouterIdValid(mPreviousRouterId), error = OT_ERROR_INVALID_STATE);
 
-    switch (aFilter)
+    switch (aMode)
     {
-    case kMleAttachSamePartition1:
-    case kMleAttachSamePartition2:
+    case kAttachSame1:
+    case kAttachSame2:
 
         // downgrade
         if (GetActiveRouterCount() > mRouterDowngradeThreshold)
@@ -393,8 +393,8 @@ otError MleRouter::HandleChildStart(otMleAttachFilter aFilter)
 
         break;
 
-    case kMleAttachAnyPartition:
-    case kMleAttachBetterPartition:
+    case kAttachAny:
+    case kAttachBetter:
         if (HasChildren() &&
             mPreviousPartitionId != mLeaderData.GetPartitionId())
         {
@@ -1330,7 +1330,7 @@ otError MleRouter::HandleAdvertisement(const Message &aMessage, const Ip6::Messa
         if (ComparePartitions(routerCount <= 1, leaderData, IsSingleton(), mLeaderData) > 0)
         {
             otLogDebgMle(GetInstance(), "trying to migrate");
-            BecomeChild(kMleAttachBetterPartition);
+            BecomeChild(kAttachBetter);
         }
 
         ExitNow(error = OT_ERROR_DROP);
@@ -1791,13 +1791,13 @@ void MleRouter::HandleStateUpdateTimer(void)
 
         if (GetLeaderAge() >= mNetworkIdTimeout)
         {
-            BecomeChild(kMleAttachSamePartition1);
+            BecomeChild(kAttachSame1);
         }
 
         if (routerStateUpdate && GetActiveRouterCount() > mRouterDowngradeThreshold)
         {
             // downgrade to REED
-            BecomeChild(kMleAttachSamePartition1);
+            BecomeChild(kAttachSame1);
         }
 
         break;
diff --git a/src/core/thread/mle_router_ftd.hpp b/src/core/thread/mle_router_ftd.hpp
index 58520756b..9acb7b97a 100644
--- a/src/core/thread/mle_router_ftd.hpp
+++ b/src/core/thread/mle_router_ftd.hpp
@@ -680,7 +680,7 @@ private:
     otError AppendPendingDataset(Message &aMessage);
     otError GetChildInfo(Child &aChild, otChildInfo &aChildInfo);
     otError HandleDetachStart(void);
-    otError HandleChildStart(otMleAttachFilter aFilter);
+    otError HandleChildStart(AttachMode aMode);
     otError HandleLinkRequest(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo);
     otError HandleLinkAccept(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo, uint32_t aKeySequence);
     otError HandleLinkAccept(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo, uint32_t aKeySequence,
diff --git a/src/core/thread/mle_router_mtd.hpp b/src/core/thread/mle_router_mtd.hpp
index 0b8aea18e..4cf21ef67 100644
--- a/src/core/thread/mle_router_mtd.hpp
+++ b/src/core/thread/mle_router_mtd.hpp
@@ -131,7 +131,7 @@ public:
 
 private:
     otError HandleDetachStart(void) { return OT_ERROR_NONE; }
-    otError HandleChildStart(otMleAttachFilter) { return OT_ERROR_NONE; }
+    otError HandleChildStart(AttachMode) { return OT_ERROR_NONE; }
     otError HandleLinkRequest(const Message &, const Ip6::MessageInfo &) { return OT_ERROR_DROP; }
     otError HandleLinkAccept(const Message &, const Ip6::MessageInfo &, uint32_t) { return OT_ERROR_DROP; }
     otError HandleLinkAccept(const Message &, const Ip6::MessageInfo &, uint32_t, bool) { return OT_ERROR_DROP; }
diff --git a/src/ncp/ncp_base.cpp b/src/ncp/ncp_base.cpp
index 9e2ed4913..5f6af7387 100644
--- a/src/ncp/ncp_base.cpp
+++ b/src/ncp/ncp_base.cpp
@@ -4576,7 +4576,7 @@ otError NcpBase::SetPropertyHandler_NET_ROLE(uint8_t header, spinel_prop_key_t k
 #endif  // OPENTHREAD_FTD
 
         case SPINEL_NET_ROLE_CHILD:
-            errorCode = otThreadBecomeChild(mInstance, kMleAttachAnyPartition);
+            errorCode = otThreadBecomeChild(mInstance);
             break;
         }