diff --git a/source/games/duke/src/dukeactor.h b/source/games/duke/src/dukeactor.h
index a6590cb9d..7df9890af 100644
--- a/source/games/duke/src/dukeactor.h
+++ b/source/games/duke/src/dukeactor.h
@@ -23,12 +23,12 @@ DDukeActor* spawn(DDukeActor* spawner, int type);
 DDukeActor* spawn(DDukeActor* actj, PClassActor* pname);
 
 // return type is int for scripting - the value must still be true or false!
-inline int badguy(DDukeActor* pSprite)
+inline int badguy(const DDukeActor* pSprite)
 {
 	return !!(pSprite->flags1 & (SFLAG_BADGUY | SFLAG_INTERNAL_BADGUY));
 }
 
-inline int bossguy(DDukeActor* pSprite)
+inline int bossguy(const DDukeActor* pSprite)
 {
 	return !!(pSprite->flags1 & SFLAG_BOSS);
 }
diff --git a/source/games/duke/src/vmexports.cpp b/source/games/duke/src/vmexports.cpp
index 4e9762e89..1308ffb3f 100644
--- a/source/games/duke/src/vmexports.cpp
+++ b/source/games/duke/src/vmexports.cpp
@@ -587,7 +587,7 @@ DEFINE_ACTION_FUNCTION_NATIVE(DDukeActor, badguy, badguy)
 	ACTION_RETURN_INT(badguy(self));
 }
 
-int duke_scripted(DDukeActor* act)
+int duke_scripted(const DDukeActor* act)
 {
 	return act->conInfo() != nullptr;
 }