diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index d91697c77..92f55da07 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -2329,8 +2329,8 @@ void Simulation::UpdateParticles(int start, int end)
 				{
 					float convGravX, convGravY;
 					GetGravityField(x, y, -2.0f, -2.0f, convGravX, convGravY);
-					auto offsetX = int(std::round(convGravX + x));
-					auto offsetY = int(std::round(convGravY + y));
+					auto offsetX = std::clamp(int(std::round(convGravX + x)), x-1, x+1);
+					auto offsetY = std::clamp(int(std::round(convGravY + y)), y-1, y+1);
 					if ((offsetX != x || offsetY != y) && offsetX >= 0 && offsetX < XRES && offsetY >= 0 && offsetY < YRES) {//some heat convection for liquids
 						auto r = pmap[offsetY][offsetX];
 						if (!(!r || parts[i].type != TYP(r))) {