diff --git a/cmd/gio/doc.go b/cmd/gio/doc.go
new file mode 100644
index 00000000..8e6e8795
--- /dev/null
+++ b/cmd/gio/doc.go
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+/*
+The gio tool builds and packages Gio programs for Android, iOS/tvOS
+and WebAssembly.
+
+Run gio with no arguments for instructions, or see the examples at
+https://gioui.org.
+*/
+package main