diff --git a/host_windows.go b/host_windows.go
index 11b0d6f..8921187 100644
--- a/host_windows.go
+++ b/host_windows.go
@@ -38,7 +38,7 @@ func HostInfo() (*HostInfoStat, error) {
 	return ret, nil
 }
 
-func BootTime() (int64, error) {
+func BootTime() (uint64, error) {
 	var lpSystemTimeAsFileTime FILETIME
 
 	r, _, _ := procGetSystemTimeAsFileTime.Call(uintptr(unsafe.Pointer(&lpSystemTimeAsFileTime)))