diff --git a/asynctools/asyncipc.nim b/asynctools/asyncipc.nim
index 2ec7905..8b4b67c 100644
--- a/asynctools/asyncipc.nim
+++ b/asynctools/asyncipc.nim
@@ -142,8 +142,19 @@ elif defined(windows):
   proc interlockedAnd(a: ptr int32, b: int32)
        {.importc: "_InterlockedAnd", header: "intrin.h".}
 
-  proc getCurrentDispatcher(): HackDispatcher =
-    result = cast[HackDispatcher](getGlobalDispatcher())
+  proc getCurrentDispatcher(): auto =
+    when defined(nimv2):
+      # New runtime will run into segfault if using HackDispatcher, but old versions of Nim require
+      # HackDispatcher so we can access some internal fields.
+      # If using the new runtime then likely using a new enough Nim version that the needed fields
+      # are exported
+      getGlobalDispatcher()
+    else:
+      cast[HackDispatcher](getGlobalDispatcher())
+
+  template getIoHandler(p: HackDispatcher): Handle =
+    ## Returns the IO handle for a dispatcher.
+    p.ioPort
 
   proc `$`*(ipc: AsyncIpc): string =
     if ipc.handleMap == Handle(0):
@@ -183,11 +194,10 @@ elif defined(windows):
     let mapSize = size + mapMinSize
 
     doAssert(size > mapMinSize)
-
     let handleMap = createFileMappingW(INVALID_HANDLE_VALUE,
                                        cast[pointer](addr sa),
                                        PAGE_READWRITE, 0, mapSize.Dword,
-                                       cast[pointer](mapName))
+                                       cast[pointer](WideCString(mapName)))
     if handleMap == 0:
       raiseOSError(osLastError())
     var eventChange = createEvent(addr sa, 0, 0, addr nameChange[0])
@@ -322,7 +332,7 @@ elif defined(windows):
   template registerWaitableChange(ipc: AsyncIpcHandle, pcd, handleCallback) =
     let p = getCurrentDispatcher()
     var flags = (WT_EXECUTEINWAITTHREAD or WT_EXECUTEONLYONCE).Dword
-    pcd.ioPort = cast[Handle](p.ioPort)
+    pcd.ioPort = p.getIoHandler()
     pcd.handleFd = AsyncFD(ipc.eventChange)
     var ol = PCustomOverlapped()
     GC_ref(ol)