diff --git a/bigint/src/algorithms.rs b/bigint/src/algorithms.rs
index d93bdd5..de99ccc 100644
--- a/bigint/src/algorithms.rs
+++ b/bigint/src/algorithms.rs
@@ -123,7 +123,6 @@ pub fn div_rem_digit(mut a: BigUint, b: BigDigit) -> (BigUint, BigDigit) {
 }
 
 // Only for the Add impl:
-#[must_use]
 #[inline]
 pub fn __add2(a: &mut [BigDigit], b: &[BigDigit]) -> BigDigit {
     debug_assert!(a.len() >= b.len());
diff --git a/bigint/src/bigint.rs b/bigint/src/bigint.rs
index bae78d7..a4505b1 100644
--- a/bigint/src/bigint.rs
+++ b/bigint/src/bigint.rs
@@ -1757,7 +1757,7 @@ fn twos_complement<'a, I>(digits: I)
     where I: IntoIterator<Item = &'a mut u8>
 {
     let mut carry = true;
-    for mut d in digits {
+    for d in digits {
         *d = d.not();
         if carry {
             *d = d.wrapping_add(1);
diff --git a/bigint/src/macros.rs b/bigint/src/macros.rs
index a1615fb..9343361 100644
--- a/bigint/src/macros.rs
+++ b/bigint/src/macros.rs
@@ -1,3 +1,5 @@
+#![allow(unknown_lints)] // older rustc doesn't know `unused_macros`
+#![allow(unused_macros)]
 
 macro_rules! forward_val_val_binop {
     (impl $imp:ident for $res:ty, $method:ident) => {
diff --git a/traits/src/bounds.rs b/traits/src/bounds.rs
index ea5c811..83fdd0f 100644
--- a/traits/src/bounds.rs
+++ b/traits/src/bounds.rs
@@ -77,17 +77,17 @@ for_each_tuple!(bounded_tuple);
 bounded_impl!(f64, f64::MIN, f64::MAX);
 
 
-macro_rules! test_wrapping_bounded {
-    ($($t:ty)+) => {
-        $(
-            assert_eq!(Wrapping::<$t>::min_value().0, <$t>::min_value());
-            assert_eq!(Wrapping::<$t>::max_value().0, <$t>::max_value());
-        )+   
-    };
-}
-
 #[test]
 fn wrapping_bounded() {
+    macro_rules! test_wrapping_bounded {
+        ($($t:ty)+) => {
+            $(
+                assert_eq!(Wrapping::<$t>::min_value().0, <$t>::min_value());
+                assert_eq!(Wrapping::<$t>::max_value().0, <$t>::max_value());
+            )+
+        };
+    }
+
     test_wrapping_bounded!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
 }
 
diff --git a/traits/src/cast.rs b/traits/src/cast.rs
index 8949834..62e6bf6 100644
--- a/traits/src/cast.rs
+++ b/traits/src/cast.rs
@@ -466,29 +466,29 @@ fn to_primitive_float() {
     assert!((f64::NAN).to_f32().map_or(false, |f| f.is_nan()));
 }
 
-macro_rules! test_wrapping_to_primitive {
-    ($($t:ty)+) => {
-        $({
-            let i: $t = 0;
-            let w = Wrapping(i);
-            assert_eq!(i.to_u8(),    w.to_u8());
-            assert_eq!(i.to_u16(),   w.to_u16());
-            assert_eq!(i.to_u32(),   w.to_u32());
-            assert_eq!(i.to_u64(),   w.to_u64());
-            assert_eq!(i.to_usize(), w.to_usize());
-            assert_eq!(i.to_i8(),    w.to_i8());
-            assert_eq!(i.to_i16(),   w.to_i16());
-            assert_eq!(i.to_i32(),   w.to_i32());
-            assert_eq!(i.to_i64(),   w.to_i64());
-            assert_eq!(i.to_isize(), w.to_isize());
-            assert_eq!(i.to_f32(),   w.to_f32());
-            assert_eq!(i.to_f64(),   w.to_f64());
-        })+   
-    };
-}
-
 #[test]
 fn wrapping_to_primitive() {
+    macro_rules! test_wrapping_to_primitive {
+        ($($t:ty)+) => {
+            $({
+                let i: $t = 0;
+                let w = Wrapping(i);
+                assert_eq!(i.to_u8(),    w.to_u8());
+                assert_eq!(i.to_u16(),   w.to_u16());
+                assert_eq!(i.to_u32(),   w.to_u32());
+                assert_eq!(i.to_u64(),   w.to_u64());
+                assert_eq!(i.to_usize(), w.to_usize());
+                assert_eq!(i.to_i8(),    w.to_i8());
+                assert_eq!(i.to_i16(),   w.to_i16());
+                assert_eq!(i.to_i32(),   w.to_i32());
+                assert_eq!(i.to_i64(),   w.to_i64());
+                assert_eq!(i.to_isize(), w.to_isize());
+                assert_eq!(i.to_f32(),   w.to_f32());
+                assert_eq!(i.to_f64(),   w.to_f64());
+            })+
+        };
+    }
+
     test_wrapping_to_primitive!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
 }
 
diff --git a/traits/src/identities.rs b/traits/src/identities.rs
index 2f520e0..79882ed 100644
--- a/traits/src/identities.rs
+++ b/traits/src/identities.rs
@@ -120,19 +120,19 @@ impl<T: One> One for Wrapping<T> where Wrapping<T>: Mul<Output=Wrapping<T>> {
 #[inline(always)] pub fn one<T: One>() -> T { One::one() }
 
 
-macro_rules! test_wrapping_identities {
-    ($($t:ty)+) => {
-        $(
-            assert_eq!(zero::<$t>(), zero::<Wrapping<$t>>().0);
-            assert_eq!(one::<$t>(), one::<Wrapping<$t>>().0);
-            assert_eq!((0 as $t).is_zero(), Wrapping(0 as $t).is_zero());
-            assert_eq!((1 as $t).is_zero(), Wrapping(1 as $t).is_zero());
-        )+   
-    };
-}
-
 #[test]
 fn wrapping_identities() {
+    macro_rules! test_wrapping_identities {
+        ($($t:ty)+) => {
+            $(
+                assert_eq!(zero::<$t>(), zero::<Wrapping<$t>>().0);
+                assert_eq!(one::<$t>(), one::<Wrapping<$t>>().0);
+                assert_eq!((0 as $t).is_zero(), Wrapping(0 as $t).is_zero());
+                assert_eq!((1 as $t).is_zero(), Wrapping(1 as $t).is_zero());
+            )+
+        };
+    }
+
     test_wrapping_identities!(isize i8 i16 i32 i64 usize u8 u16 u32 u64);
 }
 
diff --git a/traits/src/lib.rs b/traits/src/lib.rs
index 41422c8..0cfc2c7 100644
--- a/traits/src/lib.rs
+++ b/traits/src/lib.rs
@@ -361,24 +361,26 @@ fn from_str_radix_unwrap() {
     assert_eq!(f, 0.0);
 }
 
-macro_rules! test_wrapping_from_str_radix {
-    ($($t:ty)+) => {
-        $(
-            for &(s, r) in &[("42", 10), ("42", 2), ("-13.0", 10), ("foo", 10)] {
-                let w = Wrapping::<$t>::from_str_radix(s, r).map(|w| w.0);
-                assert_eq!(w, <$t as Num>::from_str_radix(s, r));
-            } 
-        )+   
-    };
-}
 #[test]
 fn wrapping_is_num() {
     fn require_num<T: Num>(_: &T) {}
     require_num(&Wrapping(42_u32));
     require_num(&Wrapping(-42));
 }
+
 #[test]
 fn wrapping_from_str_radix() {
+    macro_rules! test_wrapping_from_str_radix {
+        ($($t:ty)+) => {
+            $(
+                for &(s, r) in &[("42", 10), ("42", 2), ("-13.0", 10), ("foo", 10)] {
+                    let w = Wrapping::<$t>::from_str_radix(s, r).map(|w| w.0);
+                    assert_eq!(w, <$t as Num>::from_str_radix(s, r));
+                }
+            )+
+        };
+    }
+
     test_wrapping_from_str_radix!(usize u8 u16 u32 u64 isize i8 i16 i32 i64);
 }