diff --git a/source/games/duke/src/spawn.cpp b/source/games/duke/src/spawn.cpp
index b338d92ac..050c9250a 100644
--- a/source/games/duke/src/spawn.cpp
+++ b/source/games/duke/src/spawn.cpp
@@ -53,6 +53,8 @@ DDukeActor* EGS(sectortype* whatsectp, int s_x, int s_y, int s_z, int s_pn, int8
 {
 	// sector pointer must be strictly validated here or the engine will crash.
 	if (whatsectp == nullptr || !validSectorIndex(sectnum(whatsectp))) return nullptr;
+	// spawning out of range sprites will also crash.
+	if (s_pn < 0 || s_pn >= MAXTILES) return nullptr;
 	auto act = static_cast<DDukeActor*>(::InsertActor(RUNTIME_CLASS(DDukeActor), whatsectp, s_ss));
 
 	if (act == nullptr) return nullptr;