diff --git a/src/game/GameController.cpp b/src/game/GameController.cpp
index a4e0cccc8..5c8ed6f9a 100644
--- a/src/game/GameController.cpp
+++ b/src/game/GameController.cpp
@@ -343,6 +343,12 @@ void GameController::OpenSaveWindow()
 	}
 }
 
+void GameController::FrameStep()
+{
+	gameModel->FrameStep(1);
+	gameModel->SetPaused(true);
+}
+
 void GameController::Vote(int direction)
 {
 	if(gameModel->GetSave() && gameModel->GetUser().ID && gameModel->GetSave()->GetID() && gameModel->GetSave()->GetVote()==0)
diff --git a/src/game/GameController.h b/src/game/GameController.h
index 84af34332..0e7037198 100644
--- a/src/game/GameController.h
+++ b/src/game/GameController.h
@@ -60,6 +60,7 @@ public:
 	void Vote(int direction);
 	void ChangeBrush();
 	void ShowConsole();
+	void FrameStep();
 	ui::Point PointTranslate(ui::Point point);
 };
 
diff --git a/src/game/GameModel.cpp b/src/game/GameModel.cpp
index c026da89a..6fc9dea99 100644
--- a/src/game/GameModel.cpp
+++ b/src/game/GameModel.cpp
@@ -277,6 +277,11 @@ bool GameModel::GetPaused()
 	return sim->sys_pause?true:false;
 }
 
+void GameModel::FrameStep(int frames)
+{
+	sim->framerender += frames;
+}
+
 void GameModel::ClearSimulation()
 {
 	sim->clear_sim();
diff --git a/src/game/GameModel.h b/src/game/GameModel.h
index 0d7fc3fbb..170d1ed1d 100644
--- a/src/game/GameModel.h
+++ b/src/game/GameModel.h
@@ -70,6 +70,7 @@ public:
 	vector<Tool*> GetToolList();
 	void SetActiveMenu(Menu * menu);
 	Menu * GetActiveMenu();
+	void FrameStep(int frames);
 	User GetUser();
 	void SetUser(User user);
 	void SetBrush(int i);
diff --git a/src/game/GameView.cpp b/src/game/GameView.cpp
index e93b9b7b2..9e4a6dd70 100644
--- a/src/game/GameView.cpp
+++ b/src/game/GameView.cpp
@@ -513,6 +513,9 @@ void GameView::OnKeyPress(int key, Uint16 character, bool shift, bool ctrl, bool
 	case '`':
 		c->ShowConsole();
 		break;
+	case 'f':
+		c->FrameStep();
+		break;
 	}
 }
 
diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index 11414eafc..9e58f2299 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -2076,7 +2076,7 @@ void Simulation::update_particles_i(int start, int inc)
 	int lighting_ok=1;
 	float pGravX, pGravY, pGravD;
 
-	if (sys_pause&&lighting_recreate>0)
+	if (lighting_recreate>0)
     {
         for (i=0; i<=parts_lastActiveIndex; i++)
         {
@@ -2097,8 +2097,8 @@ void Simulation::update_particles_i(int start, int inc)
     if (lighting_recreate>21)
         lighting_recreate=21;
 
-	if (sys_pause&&!framerender)//do nothing if paused
-		return;
+	//if (sys_pause&&!framerender)//do nothing if paused
+	//	return;
 
 	//wire!
 	if(elementCount[PT_WIRE] > 0)
@@ -3078,7 +3078,8 @@ void Simulation::update_particles()//doesn't update the particles themselves, bu
 	pthread_t *InterThreads;
 #endif
 
-	air->update_air();
+	if(!sys_pause||framerender)
+		air->update_air();
 
 	memset(pmap, 0, sizeof(pmap));
 	memset(photons, 0, sizeof(photons));
@@ -3130,8 +3131,11 @@ void Simulation::update_particles()//doesn't update the particles themselves, bu
 		}
 	}
 
-	update_particles_i(0, 1);
+	if(!sys_pause||framerender)
+		update_particles_i(0, 1);
 
+	if(framerender)
+		framerender--;
 	// this should probably be elsewhere
 	/*for (y=0; y<YRES/CELL; y++)
 		for (x=0; x<XRES/CELL; x++)