diff --git a/apps/nccl/src/nccl.cu b/apps/nccl/src/nccl.cu
index 5c19dc6..5fb99ef 100644
--- a/apps/nccl/src/nccl.cu
+++ b/apps/nccl/src/nccl.cu
@@ -85,6 +85,7 @@ struct ncclComm {
   std::unordered_map<channelKey, ChannelInfo> channelInInfos;
   std::unordered_map<channelKey, ChannelInfo> channelOutInfos;
   std::unordered_map<channelKey, ChannelInfo> channelScratchInfos;
+  std::unordered_map<channelKey, cudaIpcMemHandle_t> regHandles;
   std::unordered_map<void*, channelKey> handleKeys;
   std::shared_ptr<char> scratchBuff;
   std::vector<mscclpp::RegisteredMemory> remoteScratchRegMemories;
@@ -616,6 +617,11 @@ NCCL_API ncclResult_t ncclCommRegister(ncclComm_t comm, void* buff, size_t size,
   p->ipcHandle = ipcHandle;
   *handle = p;
 
+  auto regIt = comm->regHandles.find(buffKey);
+  if (regIt == comm->regHandles.end()) {
+        comm->regHandles[buffKey] = ipcHandle;
+  }
+
   auto it = comm->handleKeys.find(*handle);
   if (it == comm->handleKeys.end()) {
      comm->handleKeys[*handle] = buffKey;
@@ -642,6 +648,7 @@ NCCL_API ncclResult_t ncclCommDeregister(ncclComm_t comm, void* handle) {
      if (outIt != comm->channelOutInfos.end()) {
         comm->channelOutInfos.erase(outIt);
      }
+     comm->regHandles.erase(buffKey);
      comm->handleKeys.erase(handle);
      free(handle);
   }
@@ -655,8 +662,8 @@ bool mscclpp_BuffIsRegistered(ncclComm_t comm, const void* buff){
   CUdeviceptr buffBasePtr;
   MSCCLPP_CUTHROW(cuMemGetAddressRange(&buffBasePtr, &buffBytes, (CUdeviceptr)buff));
   channelKey buffKey{(void*)buffBasePtr, buffBytes};
-  auto buffIt = comm->channelScratchInfos.find(buffKey);
-  bool registered =  buffIt != comm->channelScratchInfos.end();
+  auto buffIt = comm->regHandles.find(buffKey);
+  bool registered =  buffIt != comm->regHandles.end();
   return registered;
 }
 size_t