diff --git a/src/collision.h b/src/collision.h
index b0bb803..de61eda 100644
--- a/src/collision.h
+++ b/src/collision.h
@@ -6,7 +6,7 @@
 #include "format.h"
 
 struct Collision {
-    enum Side { NONE, LEFT, RIGHT, FRONT, TOP, BOTTOM } side;
+    enum Side { NONE, LEFT, RIGHT, FRONT, BACK, TOP, BOTTOM } side;
 
     struct Info {
         int room, roomAbove, roomBelow, floor, ceiling;
@@ -67,7 +67,7 @@ struct Collision {
         } else
             return;
 
-        pos += vec3(d.x, 0.0f, d.y);
+        pos += vec3(d.x, -velocity.y, d.y);
     }
 
     inline bool checkHeight(TR::Level *level, int roomIndex, const vec3 &pos, const vec2 &offset, int height, int maxAscent, int maxDescent, Side side) {