diff --git a/src/simulation/elements/LSNS.cpp b/src/simulation/elements/LSNS.cpp
index dfe941157..f65a956d2 100644
--- a/src/simulation/elements/LSNS.cpp
+++ b/src/simulation/elements/LSNS.cpp
@@ -60,6 +60,8 @@ static int update(UPDATE_FUNC_ARGS)
 				if (BOUNDS_CHECK && (rx || ry))
 				{
 					int r = pmap[y + ry][x + rx];
+					if (!r)
+						r = sim->photons[y + ry][x + rx];
 					if (!r)
 						continue;
 					int rt = TYP(r);
diff --git a/src/simulation/elements/TSNS.cpp b/src/simulation/elements/TSNS.cpp
index 198ab79d1..3282bf835 100644
--- a/src/simulation/elements/TSNS.cpp
+++ b/src/simulation/elements/TSNS.cpp
@@ -60,6 +60,8 @@ static int update(UPDATE_FUNC_ARGS)
 				if (BOUNDS_CHECK && (rx || ry))
 				{
 					int r = pmap[y+ry][x+rx];
+					if (!r)
+						r = sim->photons[y+ry][x+rx];
 					if (!r)
 						continue;
 					int rt = TYP(r);