diff --git a/src/simulation/elements/PTNM.cpp b/src/simulation/elements/PTNM.cpp
index cd7c7cab95..55b22365c2 100644
--- a/src/simulation/elements/PTNM.cpp
+++ b/src/simulation/elements/PTNM.cpp
@@ -238,7 +238,7 @@ static int update(UPDATE_FUNC_ARGS)
 						break;
 
 					case PT_RSST: // RSST -> BIZR
-						sim->part_change_type(ID(r), x + rx, y + ry, PT_BIZR);
+						sim->create_part(ID(r), x + rx, y + ry, PT_BIZR);
 						break;
 					}
 				}
diff --git a/src/simulation/elements/RSSS.cpp b/src/simulation/elements/RSSS.cpp
index 7ca3fd4241..1a11942fba 100644
--- a/src/simulation/elements/RSSS.cpp
+++ b/src/simulation/elements/RSSS.cpp
@@ -33,6 +33,7 @@ void Element::Element_RSSS()
 	Description = "Solidified resist. Blocks pressure and insulates electricity. Liquefies on contact with neutrons.";
 
 	Properties = TYPE_SOLID|PROP_NEUTPASS;
+	CarriesTypeIn = (1U << FIELD_CTYPE) | (1U << FIELD_TMP);
 
 	LowPressure = IPL;
 	LowPressureTransition = NT;
diff --git a/src/simulation/elements/RSST.cpp b/src/simulation/elements/RSST.cpp
index 747b52cedc..d12f294f86 100644
--- a/src/simulation/elements/RSST.cpp
+++ b/src/simulation/elements/RSST.cpp
@@ -61,7 +61,7 @@ int update(UPDATE_FUNC_ARGS)
 			// RSST + GUNP = FIRW
 			if(TYP(r) == PT_GUNP)
 			{
-				sim->part_change_type(i, x, y, PT_FIRW);
+				sim->create_part(i, x, y, PT_FIRW);
 				sim->kill_part(ID(r));
 				return 1;
 			}
@@ -69,7 +69,7 @@ int update(UPDATE_FUNC_ARGS)
 			// RSST + BCOL = FSEP
 			if(TYP(r) == PT_BCOL)
 			{
-				sim->part_change_type(i, x, y, PT_FSEP);
+				sim->create_part(i, x, y, PT_FSEP);
 				parts[i].life = 50;
 				sim->kill_part(ID(r));
 				return 1;