diff --git a/common/main/gameseg.h b/common/main/gameseg.h
index 858834dfd..7a83d6e46 100644
--- a/common/main/gameseg.h
+++ b/common/main/gameseg.h
@@ -73,7 +73,8 @@ static inline vms_vector compute_segment_center(vcsegptr_t sp)
 	compute_segment_center(v, sp);
 	return v;
 }
-int_fast32_t find_connect_side(vcsegptridx_t base_seg, vcsegptr_t con_seg) __attribute_warn_unused_result;
+__attribute_warn_unused_result
+uint_fast32_t find_connect_side(vcsegidx_t base_seg, const segment &con_seg);
 
 // Fill in array with four absolute point numbers for a given side
 void get_side_verts(side_vertnum_list_t &vertlist, const segment &seg, unsigned sidenum);
diff --git a/similar/main/gameseg.cpp b/similar/main/gameseg.cpp
index f2b314da8..c60712c1d 100644
--- a/similar/main/gameseg.cpp
+++ b/similar/main/gameseg.cpp
@@ -92,9 +92,19 @@ constexpr vm_distance fcd_abort_return_value{-1};
 
 }
 
+namespace dcx {
+
 // How far a point can be from a plane, and still be "in" the plane
 #define PLANE_DIST_TOLERANCE	250
 
+static uint_fast32_t find_connect_child(const vcsegidx_t base_seg, const array<segnum_t, MAX_SIDES_PER_SEGMENT> &children)
+{
+	const auto &&b = begin(children);
+	return std::distance(b, std::find(b, end(children), base_seg));
+}
+
+}
+
 namespace dsx {
 #if defined(DXX_BUILD_DESCENT_II)
 array<dl_index, MAX_DL_INDICES> Dl_indices;
@@ -131,13 +141,9 @@ void compute_segment_center(vms_vector &vp,const vcsegptr_t sp)
 // -----------------------------------------------------------------------------
 //	Given two segments, return the side index in the connecting segment which connects to the base segment
 //	Optimized by MK on 4/21/94 because it is a 2% load.
-int_fast32_t find_connect_side(const vcsegptridx_t base_seg, const vcsegptr_t con_seg)
+uint_fast32_t find_connect_side(const vcsegidx_t base_seg, const segment &con_seg)
 {
-	auto &children = con_seg->children;
-	auto b = begin(children);
-	auto i = std::find(b, end(children), base_seg);
-	// legal to return -1, used in object_move_one(), mk, 06/08/94: Assert(0);		// Illegal -- there is no connecting side between these two segments
-	return std::distance(b, i);
+	return find_connect_child(base_seg, con_seg.children);
 }
 
 }