diff --git a/stfx/clap/stfx-clap.h b/stfx/clap/stfx-clap.h
index 63b7ec4..fd67675 100644
--- a/stfx/clap/stfx-clap.h
+++ b/stfx/clap/stfx-clap.h
@@ -308,9 +308,16 @@ struct Plugin : public clap_plugin {
 		}
 		inputBuffers.resize(0);
 		outputBuffers.resize(0);
+		
+		if (plugin.effect.hasPendingWebMessage()) {
+			plugin.host->request_callback(plugin.host);
+		}
 		return CLAP_PROCESS_CONTINUE;
 	}
-	static void plugin_on_main_thread(const clap_plugin *obj) {}
+	static void plugin_on_main_thread(const clap_plugin *obj) {
+		auto &plugin = *(Plugin *)obj;
+		plugin.sendWebMessages();
+	}
 		
 	// parameters
 	struct Param : public clap_param_info {
@@ -609,7 +616,7 @@ struct Plugin : public clap_plugin {
 		if (!fillFromStream(stream, buffer)) return false;
 		StateReader storage{buffer};
 		plugin.effect.state(storage);
-		sendWebMessages(); // should already be on the main thread
+		plugin.sendWebMessages(); // should already be on the main thread
 		return true;
 	}
 	
diff --git a/stfx/ui/web-ui.h b/stfx/ui/web-ui.h
index 94797e6..4fc15c0 100644
--- a/stfx/ui/web-ui.h
+++ b/stfx/ui/web-ui.h
@@ -267,6 +267,11 @@ struct WebUIHelper {
 				readyToSend.test_and_set();
 			}
 		};
+		
+		bool hasPendingWebMessage() const {
+			auto &message = queue[readIndex];
+			return message.readyToSend.test();
+		}
 
 		// Poll on the main thread (and directly after any `.webReceive()`), calling `.sent()` after you've sent it, repeat until you get `nullptr`
 		WebMessage * getPendingWebMessage() {