diff --git a/src/elements/prti.cpp b/src/elements/prti.cpp
index 9bbbf261c..f5b237490 100644
--- a/src/elements/prti.cpp
+++ b/src/elements/prti.cpp
@@ -6,8 +6,6 @@
    PRTO does (count+4)%8, so that it will come out at the opposite place to where it came in
    PRTO does +/-1 to the count, so it doesn't jam as easily
 */
-int portal_rx[8] = {-1, 0, 1, 1, 1, 0,-1,-1};
-int portal_ry[8] = {-1,-1,-1, 0, 1, 1, 1, 0};
 
 int update_PRTI(UPDATE_FUNC_ARGS) {
 	int r, nnx, rx, ry, fe = 0;
@@ -17,8 +15,8 @@ int update_PRTI(UPDATE_FUNC_ARGS) {
 	else if (parts[i].tmp<0) parts[i].tmp = 0;
 	for (count=0; count<8; count++)
 	{
-		rx = portal_rx[count];
-		ry = portal_ry[count];
+		rx = sim->portal_rx[count];
+		ry = sim->portal_ry[count];
 			if (x+rx>=0 && y+ry>0 && x+rx<XRES && y+ry<YRES && (rx || ry))
 			{
 				r = pmap[y+ry][x+rx];
diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index 7fdd6d6fe..c266e22de 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -3372,7 +3372,9 @@ Simulation::~Simulation()
 }
 
 Simulation::Simulation():
-	sys_pause(0)
+	sys_pause(0),
+	portal_rx({-1, 0, 1, 1, 1, 0,-1,-1}),
+	portal_ry({-1,-1,-1, 0, 1, 1, 1, 0})
 {
 	//Create and attach gravity simulation
 	grav = new Gravity();
@@ -3397,6 +3399,7 @@ Simulation::Simulation():
 	pv = air->pv;
 	hv = air->hv;
 
+	//Clear signs
 	signs = (sign*)calloc(MAXSIGNS, sizeof(sign));
 
 	int menuCount;