diff --git a/go.mod b/go.mod
index baf7b50..e0d90d7 100644
--- a/go.mod
+++ b/go.mod
@@ -4,5 +4,5 @@ go 1.22.0
 
 require (
 	git.akyoto.dev/go/assert v0.1.3
-	golang.org/x/sys v0.18.0
+	golang.org/x/sys v0.30.0
 )
diff --git a/go.sum b/go.sum
index 895b93c..ed6101f 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,4 @@
 git.akyoto.dev/go/assert v0.1.3 h1:QwCUbmG4aZYsNk/OuRBz1zWVKmGlDUHhOnnDBfn8Qw8=
 git.akyoto.dev/go/assert v0.1.3/go.mod h1:0GzMaM0eURuDwtGkJJkCsI7r2aUKr+5GmWNTFPgDocM=
-golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
-golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
diff --git a/tty/Terminal_windows.go b/tty/Terminal_windows.go
index 48257c4..c7355d1 100644
--- a/tty/Terminal_windows.go
+++ b/tty/Terminal_windows.go
@@ -1,6 +1,10 @@
 package tty
 
+import "golang.org/x/sys/windows"
+
 // IsTerminal returns true if the file descriptor is a terminal.
 func IsTerminal(fd uintptr) bool {
-	return false
+	var mode uint32
+	err := windows.GetConsoleMode(windows.Handle(fd), &mode)
+	return err == nil
 }