diff --git a/examples/Example.java b/examples/Example.java
index 19150430..e8016523 100644
--- a/examples/Example.java
+++ b/examples/Example.java
@@ -202,6 +202,6 @@ public void accept(Event e) {
     public static void main(String[] args) {
         App.init();
         new Example();
-        App.run();
+        App.start();
     }
 }
diff --git a/macos/cc/App.mm b/macos/cc/App.mm
index fc747e07..358fdef0 100644
--- a/macos/cc/App.mm
+++ b/macos/cc/App.mm
@@ -34,7 +34,7 @@
     [pool release];
 }
 
-extern "C" JNIEXPORT jint JNICALL Java_org_jetbrains_jwm_App_run
+extern "C" JNIEXPORT jint JNICALL Java_org_jetbrains_jwm_App_start
   (JNIEnv* env, jclass jclass) {
     [NSApp run];
     return EXIT_SUCCESS;
@@ -44,4 +44,18 @@
   (JNIEnv* env, jclass jclass) {
     [NSApp stop:nil];
     [NSApp terminate:nil];
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_jwm_App_runOnUIThread
+  (JNIEnv* env, jclass jclass, jobject callback) {
+    JavaVM* javaVM;
+    env->GetJavaVM(&javaVM);
+    auto callbackRef = env->NewGlobalRef(callback);
+    dispatch_async(dispatch_get_main_queue(), ^{
+        JNIEnv* env2;
+        if (javaVM->GetEnv(reinterpret_cast<void**>(&env2), JNI_VERSION_1_8) == JNI_OK) {
+          jwm::classes::Runnable::run(env2, callbackRef);
+          env2->DeleteGlobalRef(callbackRef);
+        }
+    });
 }
\ No newline at end of file
diff --git a/shared/cc/impl/Library.cc b/shared/cc/impl/Library.cc
index 27edcb43..311d3cbf 100644
--- a/shared/cc/impl/Library.cc
+++ b/shared/cc/impl/Library.cc
@@ -35,10 +35,26 @@ namespace jwm {
                 Throwable::exceptionThrown(env);
             }
 
-            void accept(JNIEnv* env, jobject consumer, jobject event) {
+            bool accept(JNIEnv* env, jobject consumer, jobject event) {
                 env->CallVoidMethod(consumer, kAccept, event);
+                return Throwable::exceptionThrown(env);
+            }
+        }
+
+        namespace Runnable {
+            jmethodID kRun;
+
+            void onLoad(JNIEnv* env) {
+                jclass cls = env->FindClass("java/lang/Runnable");
+                Throwable::exceptionThrown(env);
+                kRun = env->GetMethodID(cls, "run", "()V");
                 Throwable::exceptionThrown(env);
             }
+
+            bool run(JNIEnv* env, jobject runnable) {
+                env->CallVoidMethod(runnable, kRun);
+                return Throwable::exceptionThrown(env);
+            }
         }
 
         namespace Native {
@@ -147,6 +163,7 @@ extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_jwm_impl_Library__1nAfterLo
   (JNIEnv* env, jclass jclass) {
     jwm::classes::Throwable::onLoad(env);
     jwm::classes::Consumer::onLoad(env);
+    jwm::classes::Runnable::onLoad(env);
     jwm::classes::Native::onLoad(env);
     jwm::classes::EventClose::onLoad(env);
     jwm::classes::EventKeyboard::onLoad(env);
diff --git a/shared/cc/impl/Library.hh b/shared/cc/impl/Library.hh
index 2867b566..c312f095 100644
--- a/shared/cc/impl/Library.hh
+++ b/shared/cc/impl/Library.hh
@@ -19,7 +19,12 @@ namespace jwm {
 
         namespace Consumer {
             extern jmethodID kAccept;
-            void accept(JNIEnv* env, jobject consumer, jobject event);
+            bool accept(JNIEnv* env, jobject consumer, jobject event);
+        }
+
+        namespace Runnable {
+            extern jmethodID kRun;
+            bool run(JNIEnv* env, jobject runnable);
         }
 
         namespace Native {
diff --git a/shared/java/App.java b/shared/java/App.java
index 16bf857f..8e53ef92 100644
--- a/shared/java/App.java
+++ b/shared/java/App.java
@@ -36,7 +36,9 @@ public static Window makeWindow() {
     /**
      * Will block until you call {@link #terminate()}
      */
-    public static native int run();
+    public static native int start();
+
+    public static native void runOnUIThread(Runnable callback);
 
     public static native void terminate();