Rng: impl for unsized RngCore
diff --git a/src/distributions/other.rs b/src/distributions/other.rs
index 3d797cf..084354d 100644
--- a/src/distributions/other.rs
+++ b/src/distributions/other.rs
@@ -165,7 +165,7 @@
     
     #[test]
     fn test_misc() {
-        let mut rng: &mut RngCore = &mut ::test::rng(820);
+        let rng: &mut RngCore = &mut ::test::rng(820);
         
         rng.sample::<char, _>(Uniform);
         rng.sample::<bool, _>(Uniform);
diff --git a/src/lib.rs b/src/lib.rs
index 84b90e6..37ef5f2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -659,7 +659,7 @@
     }
 }
 
-impl<R: RngCore> Rng for R {}
+impl<R: RngCore + ?Sized> Rng for R {}
 
 /// Trait for casting types to byte slices
 ///