diff --git a/src/playsim/p_map.cpp b/src/playsim/p_map.cpp
index 36c672361..d01a71856 100644
--- a/src/playsim/p_map.cpp
+++ b/src/playsim/p_map.cpp
@@ -119,7 +119,7 @@ TArray<spechit_t> portalhit;
 //
 //==========================================================================
 
-bool P_ShouldPassThroughPlayer(AActor *self, AActor *other)
+static inline bool P_ShouldPassThroughPlayer(AActor *self, AActor *other)
 {
 	if (!(dmflags3 & DF3_NO_PLAYER_CLIP))
 		return false;