diff --git a/main.go b/main.go
index f056ebb..422ecbe 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,6 @@ import (
 	// "flag"
 	"os"
 	"os/exec"
-	"os/signal"
 	"runtime"
 	// "runtime/pprof"
 	"sync"
@@ -17,29 +16,6 @@ var (
 	relaunch bool
 )
 
-func sigHandler() {
-	// TODO On Windows, these signals will not be triggered on closing cmd
-	// window. How to detect this?
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM, syscall.SIGUSR1)
-
-	for sig := range sigChan {
-		// May handle other signals in the future.
-		info.Printf("%v caught, exit\n", sig)
-		storeSiteStat(siteStatExit)
-		if sig == syscall.SIGUSR1 {
-			relaunch = true
-		}
-		close(quit)
-		break
-	}
-	/*
-		if *cpuprofile != "" {
-			pprof.StopCPUProfile()
-		}
-	*/
-}
-
 // This code is from goagain
 func lookPath() (argv0 string, err error) {
 	argv0, err = exec.LookPath(os.Args[0])
diff --git a/main_unix.go b/main_unix.go
new file mode 100644
index 0000000..bd780bd
--- /dev/null
+++ b/main_unix.go
@@ -0,0 +1,30 @@
+// +build darwin freebsd linux netbsd openbsd
+
+package main
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func sigHandler() {
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM, syscall.SIGUSR1)
+
+	for sig := range sigChan {
+		// May handle other signals in the future.
+		info.Printf("%v caught, exit\n", sig)
+		storeSiteStat(siteStatExit)
+		if sig == syscall.SIGUSR1 {
+			relaunch = true
+		}
+		close(quit)
+		break
+	}
+	/*
+		if *cpuprofile != "" {
+			pprof.StopCPUProfile()
+		}
+	*/
+}
diff --git a/main_windows.go b/main_windows.go
new file mode 100644
index 0000000..cd8393e
--- /dev/null
+++ b/main_windows.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func sigHandler() {
+	// TODO On Windows, these signals will not be triggered on closing cmd
+	// window. How to detect this?
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	for sig := range sigChan {
+		// May handle other signals in the future.
+		info.Printf("%v caught, exit\n", sig)
+		storeSiteStat(siteStatExit)
+		// Windows has no SIGUSR1 signal, so relaunching is not supported now.
+		/*
+			if sig == syscall.SIGUSR1 {
+				relaunch = true
+			}
+		*/
+		close(quit)
+		break
+	}
+	/*
+		if *cpuprofile != "" {
+			pprof.StopCPUProfile()
+		}
+	*/
+}