diff --git a/ion/src/simulator/shared/timing_msleep.cpp b/ion/src/simulator/shared/timing_msleep.cpp
index f7ab7565e..128330a0a 100644
--- a/ion/src/simulator/shared/timing_msleep.cpp
+++ b/ion/src/simulator/shared/timing_msleep.cpp
@@ -1,6 +1,10 @@
 #include <ion/timing.h>
+#include "window.h"
 #include <SDL.h>
 
 void Ion::Timing::msleep(uint32_t ms) {
+  if (Ion::Simulator::Window::isHeadless()) {
+    return;
+  }
   SDL_Delay(ms);
 }