diff --git a/src/p_local.h b/src/p_local.h
index f7e4f8285..8206c8370 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -309,7 +309,6 @@ void P_RecalcPrecipInSector(sector_t *sector);
 void P_PrecipitationEffects(void);
 
 void P_RemoveMobj(mobj_t *th);
-boolean P_MobjWasRemoved(mobj_t *th);
 void P_RemoveSavegameMobj(mobj_t *th);
 boolean P_SetPlayerMobjState(mobj_t *mobj, statenum_t state);
 boolean P_SetMobjState(mobj_t *mobj, statenum_t state);
@@ -326,6 +325,12 @@ boolean P_RailThinker(mobj_t *mobj);
 void P_PushableThinker(mobj_t *mobj);
 void P_SceneryThinker(mobj_t *mobj);
 
+// This does not need to be added to Lua.
+// To test it in Lua, check mobj.valid
+FUNCINLINE static ATTRINLINE boolean P_MobjWasRemoved(mobj_t *mobj)
+{
+	return mobj == NULL || mobj->thinker.function.acp1 != (actionf_p1)P_MobjThinker;
+}
 
 fixed_t P_MobjFloorZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect);
 fixed_t P_MobjCeilingZ(mobj_t *mobj, sector_t *sector, sector_t *boundsec, fixed_t x, fixed_t y, line_t *line, boolean lowest, boolean perfect);
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 0e1d1273c..a7e540177 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -11518,15 +11518,6 @@ void P_RemoveMobj(mobj_t *mobj)
 
 }
 
-// This does not need to be added to Lua.
-// To test it in Lua, check mobj.valid
-boolean P_MobjWasRemoved(mobj_t *mobj)
-{
-	if (mobj && mobj->thinker.function.acp1 == (actionf_p1)P_MobjThinker)
-		return false;
-	return true;
-}
-
 void P_FreePrecipMobj(precipmobj_t *mobj)
 {
 	// unlink from sector and block lists