diff --git a/doc.go b/doc.go
index 1b4f2275e..a52aa149c 100644
--- a/doc.go
+++ b/doc.go
@@ -96,8 +96,8 @@
 // `ebitenexternaldll` works only for Windows.
 // The executable will require a DLL file at the working directory. Copy them from Ebiten repository's `internal/glfw`:
 //
-//   * `glfw_windows_386.dll` for Windows 386
-//   * `glfw_windows_amd64.dll` for Windows amd64
+//   * `glfw_windows_386.dll` for Windows GOARCH=386
+//   * `glfw_windows_amd64.dll` for Windows GOARCH=amd64
 //
 // The directory path can be obtained by Go commands. For example, on PowerShell:
 //