diff --git a/CHANGELOG.md b/CHANGELOG.md
index e71c8486e8..fc49aaa74e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,8 @@ and this project adheres to
   `Decimal{,256}::checked_pow`.
 - cosmwasm-std: Implement `Sub`/`SubAssign` for `Uint64`.
 - cosmwasm-std: Implement `Mul`/`MulAssign` for `Uint64`.
+- cosmwasm-std: Implement `RemAssign` for
+  `Uint64`/`Uint128`/`Uint256`/`Uint512`.
 - cosmwasm-crypto: Upgrade ed25519-zebra to version 3.
 
 ### Changed
diff --git a/packages/std/src/math/mod.rs b/packages/std/src/math/mod.rs
index f3bd7f0168..b52730a31e 100644
--- a/packages/std/src/math/mod.rs
+++ b/packages/std/src/math/mod.rs
@@ -41,8 +41,8 @@ mod tests {
         + DivAssign<&'a Self>
         + Rem
         + Rem<&'a Self>
-        // + RemAssign
-        // + RemAssign<&'a Self>
+        + RemAssign
+        + RemAssign<&'a Self>
         + Sized
         + Copy
     where
diff --git a/packages/std/src/math/uint128.rs b/packages/std/src/math/uint128.rs
index b72392ece3..1654485809 100644
--- a/packages/std/src/math/uint128.rs
+++ b/packages/std/src/math/uint128.rs
@@ -4,7 +4,7 @@ use serde::{de, ser, Deserialize, Deserializer, Serialize};
 use std::convert::{TryFrom, TryInto};
 use std::fmt::{self};
 use std::ops::{
-    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Shr, ShrAssign, Sub, SubAssign,
+    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, RemAssign, Shr, ShrAssign, Sub, SubAssign,
 };
 use std::str::FromStr;
 
@@ -374,6 +374,13 @@ impl Rem for Uint128 {
 }
 forward_ref_binop!(impl Rem, rem for Uint128, Uint128);
 
+impl RemAssign<Uint128> for Uint128 {
+    fn rem_assign(&mut self, rhs: Uint128) {
+        *self = *self % rhs;
+    }
+}
+forward_ref_op_assign!(impl RemAssign, rem_assign for Uint128, Uint128);
+
 impl ShrAssign<u32> for Uint128 {
     fn shr_assign(&mut self, rhs: u32) {
         *self = *self >> rhs;
@@ -852,4 +859,36 @@ mod tests {
     fn uint128_rem_panics_for_zero() {
         let _ = Uint128::new(10) % Uint128::zero();
     }
+
+    #[test]
+    #[allow(clippy::op_ref)]
+    fn uint128_rem_works() {
+        assert_eq!(
+            Uint128::from(12u32) % Uint128::from(10u32),
+            Uint128::from(2u32)
+        );
+        assert_eq!(Uint128::from(50u32) % Uint128::from(5u32), Uint128::zero());
+
+        // works for refs
+        let a = Uint128::from(42u32);
+        let b = Uint128::from(5u32);
+        let expected = Uint128::from(2u32);
+        assert_eq!(a % b, expected);
+        assert_eq!(a % &b, expected);
+        assert_eq!(&a % b, expected);
+        assert_eq!(&a % &b, expected);
+    }
+
+    #[test]
+    fn uint128_rem_assign_works() {
+        let mut a = Uint128::from(30u32);
+        a %= Uint128::from(4u32);
+        assert_eq!(a, Uint128::from(2u32));
+
+        // works for refs
+        let mut a = Uint128::from(25u32);
+        let b = Uint128::from(6u32);
+        a %= &b;
+        assert_eq!(a, Uint128::from(1u32));
+    }
 }
diff --git a/packages/std/src/math/uint256.rs b/packages/std/src/math/uint256.rs
index c882c162f7..824613f7de 100644
--- a/packages/std/src/math/uint256.rs
+++ b/packages/std/src/math/uint256.rs
@@ -4,7 +4,8 @@ use serde::{de, ser, Deserialize, Deserializer, Serialize};
 use std::convert::{TryFrom, TryInto};
 use std::fmt;
 use std::ops::{
-    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Shl, Shr, ShrAssign, Sub, SubAssign,
+    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, RemAssign, Shl, Shr, ShrAssign, Sub,
+    SubAssign,
 };
 use std::str::FromStr;
 
@@ -449,6 +450,13 @@ impl Rem for Uint256 {
 }
 forward_ref_binop!(impl Rem, rem for Uint256, Uint256);
 
+impl RemAssign<Uint256> for Uint256 {
+    fn rem_assign(&mut self, rhs: Uint256) {
+        *self = *self % rhs;
+    }
+}
+forward_ref_op_assign!(impl RemAssign, rem_assign for Uint256, Uint256);
+
 impl Mul<Uint256> for Uint256 {
     type Output = Self;
 
@@ -1431,4 +1439,36 @@ mod tests {
     fn uint256_rem_panics_for_zero() {
         let _ = Uint256::from(10u32) % Uint256::zero();
     }
+
+    #[test]
+    #[allow(clippy::op_ref)]
+    fn uint256_rem_works() {
+        assert_eq!(
+            Uint256::from(12u32) % Uint256::from(10u32),
+            Uint256::from(2u32)
+        );
+        assert_eq!(Uint256::from(50u32) % Uint256::from(5u32), Uint256::zero());
+
+        // works for refs
+        let a = Uint256::from(42u32);
+        let b = Uint256::from(5u32);
+        let expected = Uint256::from(2u32);
+        assert_eq!(a % b, expected);
+        assert_eq!(a % &b, expected);
+        assert_eq!(&a % b, expected);
+        assert_eq!(&a % &b, expected);
+    }
+
+    #[test]
+    fn uint256_rem_assign_works() {
+        let mut a = Uint256::from(30u32);
+        a %= Uint256::from(4u32);
+        assert_eq!(a, Uint256::from(2u32));
+
+        // works for refs
+        let mut a = Uint256::from(25u32);
+        let b = Uint256::from(6u32);
+        a %= &b;
+        assert_eq!(a, Uint256::from(1u32));
+    }
 }
diff --git a/packages/std/src/math/uint512.rs b/packages/std/src/math/uint512.rs
index bbb8834673..6c65f3bad9 100644
--- a/packages/std/src/math/uint512.rs
+++ b/packages/std/src/math/uint512.rs
@@ -4,7 +4,7 @@ use serde::{de, ser, Deserialize, Deserializer, Serialize};
 use std::convert::{TryFrom, TryInto};
 use std::fmt;
 use std::ops::{
-    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Shr, ShrAssign, Sub, SubAssign,
+    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, RemAssign, Shr, ShrAssign, Sub, SubAssign,
 };
 use std::str::FromStr;
 
@@ -540,6 +540,13 @@ impl Rem for Uint512 {
 }
 forward_ref_binop!(impl Rem, rem for Uint512, Uint512);
 
+impl RemAssign<Uint512> for Uint512 {
+    fn rem_assign(&mut self, rhs: Uint512) {
+        *self = *self % rhs;
+    }
+}
+forward_ref_op_assign!(impl RemAssign, rem_assign for Uint512, Uint512);
+
 impl Mul<Uint512> for Uint512 {
     type Output = Self;
 
@@ -1155,4 +1162,36 @@ mod tests {
     fn uint512_rem_panics_for_zero() {
         let _ = Uint512::from(10u32) % Uint512::zero();
     }
+
+    #[test]
+    #[allow(clippy::op_ref)]
+    fn uint512_rem_works() {
+        assert_eq!(
+            Uint512::from(12u32) % Uint512::from(10u32),
+            Uint512::from(2u32)
+        );
+        assert_eq!(Uint512::from(50u32) % Uint512::from(5u32), Uint512::zero());
+
+        // works for refs
+        let a = Uint512::from(42u32);
+        let b = Uint512::from(5u32);
+        let expected = Uint512::from(2u32);
+        assert_eq!(a % b, expected);
+        assert_eq!(a % &b, expected);
+        assert_eq!(&a % b, expected);
+        assert_eq!(&a % &b, expected);
+    }
+
+    #[test]
+    fn uint512_rem_assign_works() {
+        let mut a = Uint512::from(30u32);
+        a %= Uint512::from(4u32);
+        assert_eq!(a, Uint512::from(2u32));
+
+        // works for refs
+        let mut a = Uint512::from(25u32);
+        let b = Uint512::from(6u32);
+        a %= &b;
+        assert_eq!(a, Uint512::from(1u32));
+    }
 }
diff --git a/packages/std/src/math/uint64.rs b/packages/std/src/math/uint64.rs
index 99990ed3a8..3e6ec72dc0 100644
--- a/packages/std/src/math/uint64.rs
+++ b/packages/std/src/math/uint64.rs
@@ -4,7 +4,7 @@ use serde::{de, ser, Deserialize, Deserializer, Serialize};
 use std::convert::{TryFrom, TryInto};
 use std::fmt::{self};
 use std::ops::{
-    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, Shr, ShrAssign, Sub, SubAssign,
+    Add, AddAssign, Div, DivAssign, Mul, MulAssign, Rem, RemAssign, Shr, ShrAssign, Sub, SubAssign,
 };
 
 use crate::errors::{DivideByZeroError, OverflowError, OverflowOperation, StdError};
@@ -281,6 +281,13 @@ impl Rem for Uint64 {
 }
 forward_ref_binop!(impl Rem, rem for Uint64, Uint64);
 
+impl RemAssign<Uint64> for Uint64 {
+    fn rem_assign(&mut self, rhs: Uint64) {
+        *self = *self % rhs;
+    }
+}
+forward_ref_op_assign!(impl RemAssign, rem_assign for Uint64, Uint64);
+
 impl Shr<u32> for Uint64 {
     type Output = Self;
 
@@ -761,4 +768,36 @@ mod tests {
     fn uint64_rem_panics_for_zero() {
         let _ = Uint64::new(10) % Uint64::zero();
     }
+
+    #[test]
+    #[allow(clippy::op_ref)]
+    fn uint64_rem_works() {
+        assert_eq!(
+            Uint64::from(12u32) % Uint64::from(10u32),
+            Uint64::from(2u32)
+        );
+        assert_eq!(Uint64::from(50u32) % Uint64::from(5u32), Uint64::zero());
+
+        // works for refs
+        let a = Uint64::from(42u32);
+        let b = Uint64::from(5u32);
+        let expected = Uint64::from(2u32);
+        assert_eq!(a % b, expected);
+        assert_eq!(a % &b, expected);
+        assert_eq!(&a % b, expected);
+        assert_eq!(&a % &b, expected);
+    }
+
+    #[test]
+    fn uint64_rem_assign_works() {
+        let mut a = Uint64::from(30u32);
+        a %= Uint64::from(4u32);
+        assert_eq!(a, Uint64::from(2u32));
+
+        // works for refs
+        let mut a = Uint64::from(25u32);
+        let b = Uint64::from(6u32);
+        a %= &b;
+        assert_eq!(a, Uint64::from(1u32));
+    }
 }