diff --git a/ci/big_quickcheck/src/lib.rs b/ci/big_quickcheck/src/lib.rs
index 57dd8b73..41018a69 100644
--- a/ci/big_quickcheck/src/lib.rs
+++ b/ci/big_quickcheck/src/lib.rs
@@ -42,7 +42,7 @@ fn quickcheck_signed_eq_symmetric(a: BigInt, b: BigInt) -> bool {
 
 #[test]
 fn quickcheck_arith_primitive() {
-    let gen = Gen::new(usize::max_value());
+    let gen = Gen::new(usize::MAX);
     let mut qc = QuickCheck::new().gen(gen);
 
     fn test_unsigned_add_primitive(a: usize, b: usize) -> TestResult {
@@ -280,7 +280,7 @@ fn quickcheck_signed_conversion(a: BigInt, radix: u8) -> TestResult {
 
 #[test]
 fn quicktest_shift() {
-    let gen = Gen::new(usize::max_value());
+    let gen = Gen::new(usize::MAX);
     let mut qc = QuickCheck::new().gen(gen);
 
     fn test_shr_unsigned(a: u64, shift: u8) -> TestResult {
@@ -317,7 +317,7 @@ fn quicktest_shift() {
 
 #[test]
 fn quickcheck_modpow() {
-    let gen = Gen::new(usize::max_value());
+    let gen = Gen::new(usize::MAX);
     let mut qc = QuickCheck::new().gen(gen);
 
     fn simple_modpow(base: &BigInt, exponent: &BigInt, modulus: &BigInt) -> BigInt {
@@ -360,7 +360,7 @@ fn quickcheck_modpow() {
 
 #[test]
 fn quickcheck_modinv() {
-    let gen = Gen::new(usize::max_value());
+    let gen = Gen::new(usize::MAX);
     let mut qc = QuickCheck::new().gen(gen);
 
     fn test_modinv(value: i128, modulus: i128) -> TestResult {
@@ -417,7 +417,7 @@ fn quickcheck_modinv() {
 
 #[test]
 fn quickcheck_to_float_equals_i128_cast() {
-    let gen = Gen::new(usize::max_value());
+    let gen = Gen::new(usize::MAX);
     let mut qc = QuickCheck::new().gen(gen).tests(1_000_000);
 
     fn to_f32_equals_i128_cast(value: i128) -> bool {
diff --git a/ci/big_serde/src/lib.rs b/ci/big_serde/src/lib.rs
index 68c2551b..4ee7b632 100644
--- a/ci/big_serde/src/lib.rs
+++ b/ci/big_serde/src/lib.rs
@@ -155,7 +155,7 @@ fn bad_size_hint<T: Debug + DeserializeOwned + One + PartialEq + Serialize>(
     assert_tokens(&T::one(), &tokens);
 
     tokens[prefix.len()] = Token::Seq {
-        len: Some(usize::max_value()),
+        len: Some(usize::MAX),
     };
 
     catch_unwind(|| assert_ser_tokens(&T::one(), &tokens)).unwrap_err();
diff --git a/src/bigint.rs b/src/bigint.rs
index 704bb95b..ffd457da 100644
--- a/src/bigint.rs
+++ b/src/bigint.rs
@@ -8,8 +8,6 @@ use core::fmt;
 use core::hash;
 use core::ops::{Neg, Not};
 use core::str;
-use core::{i128, u128};
-use core::{i64, u64};
 
 use num_integer::{Integer, Roots};
 use num_traits::{ConstZero, Num, One, Pow, Signed, Zero};
diff --git a/src/bigint/bits.rs b/src/bigint/bits.rs
index dfb86645..93cd24c4 100644
--- a/src/bigint/bits.rs
+++ b/src/bigint/bits.rs
@@ -36,7 +36,7 @@ fn negate_carry(a: BigDigit, acc: &mut DoubleBigDigit) -> BigDigit {
 // + 1 & -ff = ...0 01 & ...f 01 = ...0 01 = + 1
 // +ff & - 1 = ...0 ff & ...f ff = ...0 ff = +ff
 // answer is pos, has length of a
-fn bitand_pos_neg(a: &mut Vec<BigDigit>, b: &[BigDigit]) {
+fn bitand_pos_neg(a: &mut [BigDigit], b: &[BigDigit]) {
     let mut carry_b = 1;
     for (ai, &bi) in a.iter_mut().zip(b.iter()) {
         let twos_b = negate_carry(bi, &mut carry_b);
@@ -202,7 +202,7 @@ fn bitor_pos_neg(a: &mut Vec<BigDigit>, b: &[BigDigit]) {
 // - 1 | +ff = ...f ff | ...0 ff = ...f ff = - 1
 // -ff | + 1 = ...f 01 | ...0 01 = ...f 01 = -ff
 // answer is neg, has length of a
-fn bitor_neg_pos(a: &mut Vec<BigDigit>, b: &[BigDigit]) {
+fn bitor_neg_pos(a: &mut [BigDigit], b: &[BigDigit]) {
     let mut carry_a = 1;
     let mut carry_or = 1;
     for (ai, &bi) in a.iter_mut().zip(b.iter()) {
diff --git a/src/bigint/convert.rs b/src/bigint/convert.rs
index f1cc2ff9..f0c29c49 100644
--- a/src/bigint/convert.rs
+++ b/src/bigint/convert.rs
@@ -50,7 +50,7 @@ impl ToPrimitive for BigInt {
                 let m: u64 = 1 << 63;
                 match n.cmp(&m) {
                     Less => Some(-(n as i64)),
-                    Equal => Some(core::i64::MIN),
+                    Equal => Some(i64::MIN),
                     Greater => None,
                 }
             }
@@ -67,7 +67,7 @@ impl ToPrimitive for BigInt {
                 let m: u128 = 1 << 127;
                 match n.cmp(&m) {
                     Less => Some(-(n as i128)),
-                    Equal => Some(core::i128::MIN),
+                    Equal => Some(i128::MIN),
                     Greater => None,
                 }
             }
@@ -179,7 +179,7 @@ impl From<i64> for BigInt {
         if n >= 0 {
             BigInt::from(n as u64)
         } else {
-            let u = core::u64::MAX - (n as u64) + 1;
+            let u = u64::MAX - (n as u64) + 1;
             BigInt {
                 sign: Minus,
                 data: BigUint::from(u),
@@ -194,7 +194,7 @@ impl From<i128> for BigInt {
         if n >= 0 {
             BigInt::from(n as u128)
         } else {
-            let u = core::u128::MAX - (n as u128) + 1;
+            let u = u128::MAX - (n as u128) + 1;
             BigInt {
                 sign: Minus,
                 data: BigUint::from(u),
diff --git a/src/biguint.rs b/src/biguint.rs
index 9bcd8966..41506055 100644
--- a/src/biguint.rs
+++ b/src/biguint.rs
@@ -8,7 +8,6 @@ use core::fmt;
 use core::hash;
 use core::mem;
 use core::str;
-use core::{u32, u64, u8};
 
 use num_integer::{Integer, Roots};
 use num_traits::{ConstZero, Num, One, Pow, ToPrimitive, Unsigned, Zero};
@@ -410,7 +409,7 @@ impl Roots for BigUint {
             _ => {
                 // Try to guess by scaling down such that it does fit in `f64`.
                 // With some (x * 2ⁿᵏ), its nth root ≈ (ⁿ√x * 2ᵏ)
-                let extra_bits = bits - (core::f64::MAX_EXP as u64 - 1);
+                let extra_bits = bits - (f64::MAX_EXP as u64 - 1);
                 let root_scale = Integer::div_ceil(&extra_bits, &n64);
                 let scale = root_scale * n64;
                 if scale < bits && bits - scale > n64 {
@@ -458,7 +457,7 @@ impl Roots for BigUint {
             _ => {
                 // Try to guess by scaling down such that it does fit in `f64`.
                 // With some (x * 2²ᵏ), its sqrt ≈ (√x * 2ᵏ)
-                let extra_bits = bits - (core::f64::MAX_EXP as u64 - 1);
+                let extra_bits = bits - (f64::MAX_EXP as u64 - 1);
                 let root_scale = (extra_bits + 1) / 2;
                 let scale = root_scale * 2;
                 (self >> scale).sqrt() << root_scale
@@ -499,7 +498,7 @@ impl Roots for BigUint {
             _ => {
                 // Try to guess by scaling down such that it does fit in `f64`.
                 // With some (x * 2³ᵏ), its cbrt ≈ (∛x * 2ᵏ)
-                let extra_bits = bits - (core::f64::MAX_EXP as u64 - 1);
+                let extra_bits = bits - (f64::MAX_EXP as u64 - 1);
                 let root_scale = (extra_bits + 2) / 3;
                 let scale = root_scale * 3;
                 (self >> scale).cbrt() << root_scale
@@ -1032,9 +1031,7 @@ impl BigUint {
         // Note: we're saturating `digit_index` and `new_len` -- any such case is guaranteed to
         // fail allocation, and that's more consistent than adding our own overflow panics.
         let bits_per_digit = u64::from(big_digit::BITS);
-        let digit_index = (bit / bits_per_digit)
-            .to_usize()
-            .unwrap_or(core::usize::MAX);
+        let digit_index = (bit / bits_per_digit).to_usize().unwrap_or(usize::MAX);
         let bit_mask = (1 as BigDigit) << (bit % bits_per_digit);
         if value {
             if digit_index >= self.data.len() {
@@ -1176,28 +1173,17 @@ cfg_digit!(
 fn test_u32_u128() {
     assert_eq!(u32_from_u128(0u128), (0, 0, 0, 0));
     assert_eq!(
-        u32_from_u128(u128::max_value()),
-        (
-            u32::max_value(),
-            u32::max_value(),
-            u32::max_value(),
-            u32::max_value()
-        )
+        u32_from_u128(u128::MAX),
+        (u32::MAX, u32::MAX, u32::MAX, u32::MAX)
     );
 
-    assert_eq!(
-        u32_from_u128(u32::max_value() as u128),
-        (0, 0, 0, u32::max_value())
-    );
+    assert_eq!(u32_from_u128(u32::MAX as u128), (0, 0, 0, u32::MAX));
 
-    assert_eq!(
-        u32_from_u128(u64::max_value() as u128),
-        (0, 0, u32::max_value(), u32::max_value())
-    );
+    assert_eq!(u32_from_u128(u64::MAX as u128), (0, 0, u32::MAX, u32::MAX));
 
     assert_eq!(
-        u32_from_u128((u64::max_value() as u128) + u32::max_value() as u128),
-        (0, 1, 0, u32::max_value() - 1)
+        u32_from_u128((u64::MAX as u128) + u32::MAX as u128),
+        (0, 1, 0, u32::MAX - 1)
     );
 
     assert_eq!(u32_from_u128(36_893_488_151_714_070_528), (0, 2, 1, 0));
@@ -1209,11 +1195,11 @@ fn test_u128_u32_roundtrip() {
     let values = vec![
         0u128,
         1u128,
-        u64::max_value() as u128 * 3,
-        u32::max_value() as u128,
-        u64::max_value() as u128,
-        (u64::max_value() as u128) + u32::max_value() as u128,
-        u128::max_value(),
+        u64::MAX as u128 * 3,
+        u32::MAX as u128,
+        u64::MAX as u128,
+        (u64::MAX as u128) + u32::MAX as u128,
+        u128::MAX,
     ];
 
     for val in &values {
diff --git a/src/biguint/addition.rs b/src/biguint/addition.rs
index 4ad00a8c..a054e66d 100644
--- a/src/biguint/addition.rs
+++ b/src/biguint/addition.rs
@@ -194,7 +194,7 @@ impl AddAssign<u128> for BigUint {
     cfg_digit!(
         #[inline]
         fn add_assign(&mut self, other: u128) {
-            if other <= u128::from(u64::max_value()) {
+            if other <= u128::from(u64::MAX) {
                 *self += other as u64
             } else {
                 let (a, b, c, d) = super::u32_from_u128(other);
diff --git a/src/biguint/convert.rs b/src/biguint/convert.rs
index 384b5f44..18c74bb3 100644
--- a/src/biguint/convert.rs
+++ b/src/biguint/convert.rs
@@ -69,7 +69,7 @@ fn from_inexact_bitwise_digits_le(v: &[u8], bits: u8) -> BigUint {
     let total_bits = (v.len() as u64).saturating_mul(bits.into());
     let big_digits = Integer::div_ceil(&total_bits, &big_digit::BITS.into())
         .to_usize()
-        .unwrap_or(core::usize::MAX);
+        .unwrap_or(usize::MAX);
     let mut data = Vec::with_capacity(big_digits);
 
     let mut d = 0;
@@ -245,7 +245,7 @@ impl Num for BigUint {
                 b'a'..=b'z' => b - b'a' + 10,
                 b'A'..=b'Z' => b - b'A' + 10,
                 b'_' => continue,
-                _ => core::u8::MAX,
+                _ => u8::MAX,
             };
             if d < radix as u8 {
                 v.push(d);
@@ -372,8 +372,8 @@ impl ToPrimitive for BigUint {
         let mantissa = high_bits_to_u64(self);
         let exponent = self.bits() - u64::from(fls(mantissa));
 
-        if exponent > core::f32::MAX_EXP as u64 {
-            Some(core::f32::INFINITY)
+        if exponent > f32::MAX_EXP as u64 {
+            Some(f32::INFINITY)
         } else {
             Some((mantissa as f32) * 2.0f32.powi(exponent as i32))
         }
@@ -384,8 +384,8 @@ impl ToPrimitive for BigUint {
         let mantissa = high_bits_to_u64(self);
         let exponent = self.bits() - u64::from(fls(mantissa));
 
-        if exponent > core::f64::MAX_EXP as u64 {
-            Some(core::f64::INFINITY)
+        if exponent > f64::MAX_EXP as u64 {
+            Some(f64::INFINITY)
         } else {
             Some((mantissa as f64) * 2.0f64.powi(exponent as i32))
         }
@@ -607,7 +607,7 @@ pub(super) fn to_bitwise_digits_le(u: &BigUint, bits: u8) -> Vec<u8> {
     let digits_per_big_digit = big_digit::BITS / bits;
     let digits = Integer::div_ceil(&u.bits(), &u64::from(bits))
         .to_usize()
-        .unwrap_or(core::usize::MAX);
+        .unwrap_or(usize::MAX);
     let mut res = Vec::with_capacity(digits);
 
     for mut r in u.data[..last_i].iter().cloned() {
@@ -633,7 +633,7 @@ fn to_inexact_bitwise_digits_le(u: &BigUint, bits: u8) -> Vec<u8> {
     let mask: BigDigit = (1 << bits) - 1;
     let digits = Integer::div_ceil(&u.bits(), &u64::from(bits))
         .to_usize()
-        .unwrap_or(core::usize::MAX);
+        .unwrap_or(usize::MAX);
     let mut res = Vec::with_capacity(digits);
 
     let mut r = 0;
@@ -845,7 +845,7 @@ fn test_radix_bases() {
     for radix in 3u32..256 {
         if !radix.is_power_of_two() {
             let (base, power) = get_radix_base(radix);
-            let radix = BigDigit::try_from(radix).unwrap();
+            let radix = BigDigit::from(radix);
             let power = u32::try_from(power).unwrap();
             assert_eq!(base, radix.pow(power));
             assert!(radix.checked_pow(power + 1).is_none());
@@ -858,7 +858,7 @@ fn test_half_radix_bases() {
     for radix in 3u32..256 {
         if !radix.is_power_of_two() {
             let (base, power) = get_half_radix_base(radix);
-            let radix = BigDigit::try_from(radix).unwrap();
+            let radix = BigDigit::from(radix);
             let power = u32::try_from(power).unwrap();
             assert_eq!(base, radix.pow(power));
             assert!(radix.pow(power + 1) > big_digit::HALF);
diff --git a/src/biguint/shift.rs b/src/biguint/shift.rs
index f603537a..edcbc158 100644
--- a/src/biguint/shift.rs
+++ b/src/biguint/shift.rs
@@ -58,7 +58,7 @@ fn biguint_shr<T: PrimInt>(n: Cow<'_, BigUint>, shift: T) -> BigUint {
         return n.into_owned();
     }
     let bits = T::from(big_digit::BITS).unwrap();
-    let digits = (shift / bits).to_usize().unwrap_or(core::usize::MAX);
+    let digits = (shift / bits).to_usize().unwrap_or(usize::MAX);
     let shift = (shift % bits).to_u8().unwrap();
     biguint_shr2(n, digits, shift)
 }
diff --git a/src/macros.rs b/src/macros.rs
index ab821907..f2e21e3b 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -2,19 +2,19 @@
 
 macro_rules! cfg_32 {
     ($($any:tt)+) => {
-        #[cfg(not(any(target_pointer_width = "64", target_pointer_width = "128")))] $($any)+
+        #[cfg(not(target_pointer_width = "64"))] $($any)+
     }
 }
 
 macro_rules! cfg_32_or_test {
     ($($any:tt)+) => {
-        #[cfg(any(not(any(target_pointer_width = "64", target_pointer_width = "128")), test))] $($any)+
+        #[cfg(any(not(target_pointer_width = "64"), test))] $($any)+
     }
 }
 
 macro_rules! cfg_64 {
     ($($any:tt)+) => {
-        #[cfg(any(target_pointer_width = "64", target_pointer_width = "128"))] $($any)+
+        #[cfg(target_pointer_width = "64")] $($any)+
     }
 }
 
diff --git a/tests/bigint.rs b/tests/bigint.rs
index 75cf81ec..fea5232e 100644
--- a/tests/bigint.rs
+++ b/tests/bigint.rs
@@ -8,9 +8,6 @@ use std::hash::{BuildHasher, Hash, Hasher};
 use std::iter::repeat;
 use std::ops::Neg;
 use std::{f32, f64};
-use std::{i128, u128};
-use std::{i16, i32, i64, i8, isize};
-use std::{u16, u32, u64, u8, usize};
 
 use num_integer::Integer;
 use num_traits::{
diff --git a/tests/bigint_bitwise.rs b/tests/bigint_bitwise.rs
index 6c1e82fe..94d92e1d 100644
--- a/tests/bigint_bitwise.rs
+++ b/tests/bigint_bitwise.rs
@@ -1,6 +1,5 @@
 use num_bigint::{BigInt, Sign, ToBigInt};
 use num_traits::ToPrimitive;
-use std::{i32, i64, u32};
 
 enum ValueVec {
     N,
diff --git a/tests/biguint.rs b/tests/biguint.rs
index c027771b..4e2c6259 100644
--- a/tests/biguint.rs
+++ b/tests/biguint.rs
@@ -6,12 +6,9 @@ use num_integer::Integer;
 use std::cmp::Ordering::{Equal, Greater, Less};
 use std::collections::hash_map::RandomState;
 use std::hash::{BuildHasher, Hash, Hasher};
-use std::i64;
 use std::iter::repeat;
 use std::str::FromStr;
 use std::{f32, f64};
-use std::{i128, u128};
-use std::{u16, u32, u64, u8, usize};
 
 use num_traits::{
     pow, CheckedAdd, CheckedDiv, CheckedMul, CheckedSub, Euclid, FromBytes, FromPrimitive, Num,
diff --git a/tests/consts/mod.rs b/tests/consts/mod.rs
index 5d0555d0..457fbd36 100644
--- a/tests/consts/mod.rs
+++ b/tests/consts/mod.rs
@@ -16,7 +16,7 @@ pub const SUM_TRIPLES: &[(&[u32], &[u32], &[u32])] = &[
     (&[1, 2, 2, 1], &[N1, N2], &[0, 1, 3, 1]),
 ];
 
-pub const M: u32 = ::std::u32::MAX;
+pub const M: u32 = u32::MAX;
 pub const MUL_TRIPLES: &[(&[u32], &[u32], &[u32])] = &[
     (&[], &[], &[]),
     (&[], &[1], &[]),
diff --git a/tests/roots.rs b/tests/roots.rs
index cfef80c4..7110adf9 100644
--- a/tests/roots.rs
+++ b/tests/roots.rs
@@ -1,7 +1,6 @@
 mod biguint {
     use num_bigint::BigUint;
     use num_traits::{One, Zero};
-    use std::{i32, u32};
 
     fn check<T: Into<BigUint>>(x: T, n: u32) {
         let x: BigUint = x.into();