diff --git a/engine/core/src/engine.cpp b/engine/core/src/engine.cpp
index 1c5dace..966d538 100755
--- a/engine/core/src/engine.cpp
+++ b/engine/core/src/engine.cpp
@@ -87,11 +87,13 @@ bool engine::is_paused() const {
 }
 
 void engine::quit() {
-    windows[0]->quit_requested = true;
+    if(!windows.empty())
+        windows[0]->quit_requested = true;
 }
 
 bool engine::is_quitting() const {
-    return windows[0]->quit_requested;
+    if(!windows.empty())
+        return windows[0]->quit_requested;
 }
 
 void engine::prepare_quit() {
diff --git a/example/include/example.hpp b/example/include/example.hpp
index be16f84..3278372 100644
--- a/example/include/example.hpp
+++ b/example/include/example.hpp
@@ -2,7 +2,7 @@
 
 #include "app.hpp"
 
-class ExampleApp : public app {
+class ExampleApp : public prism::app {
 public:
    
 };
\ No newline at end of file
diff --git a/example/src/example.cpp b/example/src/example.cpp
index 1dbb56b..f8ac293 100644
--- a/example/src/example.cpp
+++ b/example/src/example.cpp
@@ -1,5 +1,5 @@
 #include "example.hpp"
 
-void app_main(Engine* engine) {
+void app_main(prism::engine* engine) {
 
 }
\ No newline at end of file