diff --git a/source/build/include/build.h b/source/build/include/build.h
index 052d0cd36..9883ccb78 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -1174,7 +1174,8 @@ int32_t try_facespr_intersect(uspriteptr_t const spr, const vec3_t *refpos,
                                      int32_t vx, int32_t vy, int32_t vz,
                                      vec3_t *intp, int32_t strictly_smaller_than_p);
 
-bool sectoradjacent(int sect1, int sect2);
+int findwallbetweensectors(int sect1, int sect2);
+static FORCE_INLINE bool sectoradjacent(int sect1, int sect2) { return findwallbetweensectors(sect1, sect2) != -1; }
 int32_t getwalldist(vec2_t const &p, int const wallnum, vec2_t * const output = nullptr);
 int32_t getsectordist(vec2_t const &p, int const sectnum);
 extern const int16_t *chsecptr_onextwall;
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index a7ad9c3cb..cb857c869 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -10993,16 +10993,19 @@ int32_t getsectordist(vec2_t const &pos, int const sectnum)
     return distance;
 }
 
-bool sectoradjacent(int sect1, int sect2)
+int findwallbetweensectors(int sect1, int sect2)
 {
     if (sector[sect1].wallnum > sector[sect2].wallnum)
         swaplong(&sect1, &sect2);
 
-    for (int i = 0; i < sector[sect1].wallnum; i++)
-        if (wall[sector[sect1].wallptr + i].nextsector == sect2)
-            return 1;
+    auto const sec  = (usectorptr_t)&sector[sect1];
+    int const  last = sec->wallptr + sec->wallnum;
 
-    return 0;
+    for (int i = sec->wallptr; i < last; i++)
+        if (wall[i].nextsector == sect2)
+            return i;
+
+    return -1;
 }
 
 #define MAXUPDATESECTORDIST 1536