diff --git a/include/vkRenderMessages.h b/include/vkRenderMessages.h
index 7d07e9a3f..07d31458f 100644
--- a/include/vkRenderMessages.h
+++ b/include/vkRenderMessages.h
@@ -3,5 +3,8 @@
 enum VulkanRendererMessage : uint32_t
 {
   /** Export, if ready */
-  exportRender = 0
+  exportRender = 0,
+
+  /** Update the renderer */
+  updateRenderer = 1
 };
\ No newline at end of file
diff --git a/include/vkrender.h b/include/vkrender.h
index a10bde18c..b5701ddcd 100644
--- a/include/vkrender.h
+++ b/include/vkrender.h
@@ -947,6 +947,7 @@ class AsyVkRender
   static void exportHandler(int=0);
   void Export(int imageIndex);
   bool readyForExport=false;
+  bool readyForUpdate=false;
   void quit();
 
   double spinStep();
diff --git a/src/vkrender.cc b/src/vkrender.cc
index 328a88b25..8619a5e32 100644
--- a/src/vkrender.cc
+++ b/src/vkrender.cc
@@ -360,7 +360,7 @@ void AsyVkRender::framebufferResizeCallback(GLFWwindow* window, int width, int h
     static bool initialize=true;
     if(initialize) {
       initialize=false;
-      Signal(SIGUSR1,updateHandler);
+      app->readyForUpdate=true;
     }
   }
 }
@@ -646,11 +646,8 @@ void AsyVkRender::vkrender(const string& prefix, const picture* pic, const strin
 #ifdef HAVE_PTHREAD
   if(vkthread && initializedView) {
     if(View) {
-#ifdef __MSDOS__ // Signals are unreliable in MSWindows
-      vkupdate=true;
-#else
-      pthread_kill(mainthread,SIGUSR1);
-#endif
+      // called from asymain thread, main thread handles vulkan rendering
+      messageQueue.enqueue(updateRenderer);
     } else readyAfterExport=queueExport=true;
     return;
   }
@@ -3893,6 +3890,13 @@ void AsyVkRender::processMessages(VulkanRendererMessage const& msg)
       }
     }
     break;
+    case updateRenderer: {
+      if (readyForUpdate)
+      {
+        readyForUpdate=false;
+        updateHandler(0);
+      }
+    }
     default:
       break;
   }