diff --git a/agor-pty/native/agor_resize.c b/agor-pty/native/agor_resize.c
index b63ae8f..6f23009 100644
--- a/agor-pty/native/agor_resize.c
+++ b/agor-pty/native/agor_resize.c
@@ -211,6 +211,13 @@ void agor_resize_init(void *window_ptr, int border)
         webview = child;
     }
 
+    /* Set GTK window background to black (prevents white flash before WebView loads) */
+    {
+        GdkRGBA black = { 0.0, 0.0, 0.0, 1.0 };
+        gtk_widget_override_background_color(GTK_WIDGET(stored_window), GTK_STATE_FLAG_NORMAL, &black);
+        fprintf(stderr, "[agor-resize] Window background set to black\n");
+    }
+
     stored_webview = webview;
     if (webview == GTK_WIDGET(stored_window)) {
         fprintf(stderr, "[agor-resize] WARNING: no child widget found, connecting on window\n");
diff --git a/agor-pty/native/libagor-resize.so b/agor-pty/native/libagor-resize.so
index 7f222df..1544def 100755
Binary files a/agor-pty/native/libagor-resize.so and b/agor-pty/native/libagor-resize.so differ