diff --git a/app/os_darwin.go b/app/os_darwin.go
index 8f82cc94..fc5a4353 100644
--- a/app/os_darwin.go
+++ b/app/os_darwin.go
@@ -75,9 +75,13 @@ var displayLinks sync.Map
 
 var mainFuncs = make(chan func(), 1)
 
+func isMainThread() bool {
+	return bool(C.isMainThread())
+}
+
 // runOnMain runs the function on the main thread.
 func runOnMain(f func()) {
-	if C.isMainThread() {
+	if isMainThread() {
 		f()
 		return
 	}
diff --git a/app/os_macos.go b/app/os_macos.go
index cb27f942..1da5083f 100644
--- a/app/os_macos.go
+++ b/app/os_macos.go
@@ -976,6 +976,9 @@ func (w *window) init() error {
 }
 
 func osMain() {
+	if !isMainThread() {
+		panic("app.Main must run on the main goroutine")
+	}
 	C.gio_main()
 }