diff --git a/src/frustum.rs b/src/frustum.rs
index 2dc6c1d..e9e4468 100644
--- a/src/frustum.rs
+++ b/src/frustum.rs
@@ -71,15 +71,12 @@ Frustum<S> {
     pub fn contains<B: Bound<S>>(&self, bound: &B) -> Relation {
         [&self.left, &self.right, &self.top, &self.bottom, &self.near, &self.far]
             .iter().fold(Relation::In, |cur, p| {
+            use std::cmp::max;
             let r = bound.relate_plane(p);
-            // if we see Cross, then the result is Cross
-            // if we see In, then we keep the old result
-            // otherwise, take the current result
-            if cur == Relation::Cross || r == Relation::In {
-                cur
-            }else {
-                r
-            }
+            // If any of the planes are `Out`, the bound is outside.
+            // Otherwise, if any are `Cross`, the bound is crossing.
+            // Otherwise, the bound is fully inside.
+            max(cur, r)
         })
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index c0c7df8..f1eb8ef 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,7 +16,6 @@
 #![crate_type = "rlib"]
 #![crate_type = "dylib"]
 #![feature(old_impl_check, plugin, core, std_misc, custom_derive)]
-#![plugin(rand_macros)]
 
 //! Computer graphics-centric math.
 //!