diff --git a/source/build/include/build.h b/source/build/include/build.h
index 66be2f341..ed4297483 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -1169,7 +1169,7 @@ int32_t try_facespr_intersect(uspritetype const * const spr, const vec3_t *refpo
                                      vec3_t *intp, int32_t strictly_smaller_than_p);
 
 bool sectoradjacent(int sect1, int sect2);
-int32_t getwalldist(vec2_t const &p, int const wallnum);
+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;
 int32_t checksectorpointer(int16_t i, int16_t sectnum);
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index 25e7e955a..8a9b1e109 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -10971,10 +10971,11 @@ static inline bool inside_z_p(int32_t const x, int32_t const y, int32_t const z,
     return (z >= cz && z <= fz && inside_p(x, y, sectnum));
 }
 
-int32_t getwalldist(vec2_t const &p, int const wallnum)
+int32_t getwalldist(vec2_t const &p, int const wallnum, vec2_t * const output)
 {
     vec2_t closest;
     getclosestpointonwall_internal(p, wallnum, &closest);
+    if (output) *output = closest;
     return klabs(closest.x - p.x) + klabs(closest.y - p.y);
 }