diff --git a/source/build/include/build.h b/source/build/include/build.h
index 17f9d4897..88e775c74 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -208,6 +208,7 @@ void yax_setbunches(int16_t i, int16_t cb, int16_t fb);
 int16_t yax_vnextsec(int16_t line, int16_t cf);
 void yax_update(int32_t resetstat);
 int32_t yax_getneighborsect(int32_t x, int32_t y, int32_t sectnum, int32_t cf);
+void yax_getclosestpointonwall(int32_t dawall, int32_t *closestx, int32_t *closesty);
 
 static FORCE_INLINE int32_t yax_waltosecmask(int32_t walclipmask)
 {
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index a4a72d664..0579632fa 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -608,7 +608,7 @@ static int16_t *yumost=NULL, *ydmost=NULL;  // used as if [numyaxbunches][xdimen
 uint8_t haveymost[YAX_MAXBUNCHES>>3];
 
 // adapted from build.c
-static void yax_getclosestpointonwall(int32_t dawall, int32_t *closestx, int32_t *closesty)
+void yax_getclosestpointonwall(int32_t dawall, int32_t *closestx, int32_t *closesty)
 {
     int64_t i, j, wx,wy, wx2,wy2, dx, dy;