diff --git a/qbsp/brush.cc b/qbsp/brush.cc
index a23197de..bcf6dc74 100644
--- a/qbsp/brush.cc
+++ b/qbsp/brush.cc
@@ -1222,12 +1222,16 @@ Brush_LoadEntity(mapentity_t *dst, const mapentity_t *src, const int hullnum)
         if (dst != pWorldEnt())
             contents = CONTENTS_SOLID;
 
-        /* Hack to turn bmodels with "_mirrorinside" into func_detail_illusionary in hull 0.
-           this is to allow "_mirrorinside" to work on func_illusionary, etc.
+        /* Hack to turn bmodels with "_mirrorinside" into func_detail_fence in hull 0.
+           this is to allow "_mirrorinside" to work on func_illusionary, func_wall, etc.
            Otherwise they would be CONTENTS_SOLID and the inside faces would be deleted.
+         
+           It's CONTENTS_DETAIL_FENCE because this gets mapped to CONTENTS_SOLID just
+           before writing the bsp, and bmodels normally have CONTENTS_SOLID as their
+           contents type.
          */
         if (dst != pWorldEnt() && hullnum == 0 && (cflags & CFLAGS_BMODEL_MIRROR_INSIDE)) {
-            contents = CONTENTS_DETAIL_ILLUSIONARY;
+            contents = CONTENTS_DETAIL_FENCE;
         }
         
         /* nonsolid brushes don't show up in clipping hulls */