diff --git a/game.scm b/game.scm
index 7f64792..d9fe1ba 100644
--- a/game.scm
+++ b/game.scm
@@ -79,17 +79,21 @@
 (define (collide-gelement! x y parenthes)
   (dprint "x" x)
   (dprint "y" y)
-  (let ((e (vector-ref (vector-ref (level-grid *level*) y) x)))
-    (dprint "content" (parentheses-content parenthes))
-    (if (gelement-interact? (gelement-type e))
-        (begin
-          (dprint "Move!")
-          (set-grid! x y air)
-          (set-parentheses-pos! parenthes (cons x y))
-          (set-parentheses-content! parenthes (append (parentheses-content parenthes) (gelement-content e)))
-          (dprint "after-content" (parentheses-content parenthes))
-          (dprint "grid" (level-grid *level*)))
-        (dprint "Boop!"))))
+  (if (and (>= x 0) (>= y 0))
+      (let ((e (vector-ref (vector-ref (level-grid *level*) y) x))
+            (len (vector-length (level-grid *level*))))
+        (dprint "content" (parentheses-content parenthes))
+        (dprint "par pos" (parentheses-pos parenthes))
+        (if (and  (<= x len) (<= y len))
+            (if (gelement-interact? (gelement-type e))
+                (begin
+                  (dprint "Move!")
+                  (set-grid! x y air)
+                  (set-parentheses-pos! parenthes (cons x y))
+                  (set-parentheses-content! parenthes (append (parentheses-content parenthes) (gelement-content e)))
+                  (dprint "after-content" (parentheses-content parenthes)))
+                (dprint "Boop!"))))
+      (dprint "Boop!")))
 
 (define (collide-pareneheses! level)
   (let ((left-parenthes (level-left-parenthes level))