diff --git a/src/mapper/map_func.cc b/src/mapper/map_func.cc
index 8b032f2..0ba769c 100644
--- a/src/mapper/map_func.cc
+++ b/src/mapper/map_func.cc
@@ -22,6 +22,26 @@ void copy_proto_lists()
     // TODO: Incomplete.
 }
 
+// 0x484294
+void sort_rect(Rect* a, Rect* b)
+{
+    if (b->right > b->left) {
+        a->left = b->left;
+        a->right = b->right;
+    } else {
+        a->left = b->right;
+        a->right = b->left;
+    }
+
+    if (b->bottom > b->top) {
+        a->top = b->top;
+        a->bottom = b->bottom;
+    } else {
+        a->top = b->bottom;
+        a->bottom = b->top;
+    }
+}
+
 // 0x4842D4
 void draw_rect(Rect* rect, unsigned char color)
 {
diff --git a/src/mapper/map_func.h b/src/mapper/map_func.h
index 3d03b42..843f72a 100644
--- a/src/mapper/map_func.h
+++ b/src/mapper/map_func.h
@@ -7,6 +7,7 @@ namespace fallout {
 
 void setup_map_dirs();
 void copy_proto_lists();
+void sort_rect(Rect* a, Rect* b);
 void draw_rect(Rect* rect);
 void erase_rect(Rect* rect);
 int toolbar_proto(int type, int id);