diff --git a/file.go b/file.go
index 93c572b..fd16f00 100644
--- a/file.go
+++ b/file.go
@@ -13,7 +13,7 @@ import (
 //sys createIoCompletionPort(file syscall.Handle, port syscall.Handle, key uintptr, threadCount uint32) (newport syscall.Handle, err error) = CreateIoCompletionPort
 //sys getQueuedCompletionStatus(port syscall.Handle, bytes *uint32, key *uintptr, o **ioOperation, timeout uint32) (err error) = GetQueuedCompletionStatus
 //sys setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err error) = SetFileCompletionNotificationModes
-//sys timeBeginPeriod(period uint32) (n int32) = TimeBeginPeriod
+//sys timeBeginPeriod(period uint32) (n int32) = winmm.timeBeginPeriod
 
 const (
 	cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 1
diff --git a/zsyscall.go b/zsyscall.go
index 54b8332..37e8294 100644
--- a/zsyscall.go
+++ b/zsyscall.go
@@ -9,13 +9,14 @@ var _ unsafe.Pointer
 
 var (
 	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
+	modwinmm    = syscall.NewLazyDLL("winmm.dll")
 	modadvapi32 = syscall.NewLazyDLL("advapi32.dll")
 
 	procCancelIoEx                                           = modkernel32.NewProc("CancelIoEx")
 	procCreateIoCompletionPort                               = modkernel32.NewProc("CreateIoCompletionPort")
 	procGetQueuedCompletionStatus                            = modkernel32.NewProc("GetQueuedCompletionStatus")
 	procSetFileCompletionNotificationModes                   = modkernel32.NewProc("SetFileCompletionNotificationModes")
-	procTimeBeginPeriod                                      = modkernel32.NewProc("TimeBeginPeriod")
+	proctimeBeginPeriod                                      = modwinmm.NewProc("timeBeginPeriod")
 	procConnectNamedPipe                                     = modkernel32.NewProc("ConnectNamedPipe")
 	procCreateNamedPipeW                                     = modkernel32.NewProc("CreateNamedPipeW")
 	procCreateFileW                                          = modkernel32.NewProc("CreateFileW")
@@ -90,7 +91,7 @@ func setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err erro
 }
 
 func timeBeginPeriod(period uint32) (n int32) {
-	r0, _, _ := syscall.Syscall(procTimeBeginPeriod.Addr(), 1, uintptr(period), 0, 0)
+	r0, _, _ := syscall.Syscall(proctimeBeginPeriod.Addr(), 1, uintptr(period), 0, 0)
 	n = int32(r0)
 	return
 }