diff --git a/substrate/primitives/arithmetic/src/helpers_128bit.rs b/substrate/primitives/arithmetic/src/helpers_128bit.rs
index 260f90ed60..11df8bd531 100644
--- a/substrate/primitives/arithmetic/src/helpers_128bit.rs
+++ b/substrate/primitives/arithmetic/src/helpers_128bit.rs
@@ -358,8 +358,8 @@ mod tests {
 	fn op_checked_rounded_div_works() {
 		for i in 0..100_000u32 {
 			let a = random_u128(i);
-			let b = random_u128(i + 1 << 30);
-			let c = random_u128(i + 1 << 31);
+			let b = random_u128(i + (1 << 30));
+			let c = random_u128(i + (1 << 31));
 			let x = mulrat(a, b, c, NearestPrefDown);
 			let y = multiply_by_rational(a, b, c).ok();
 			assert_eq!(x.is_some(), y.is_some());
diff --git a/substrate/primitives/arithmetic/src/per_things.rs b/substrate/primitives/arithmetic/src/per_things.rs
index 7f39d35774..2932a74206 100644
--- a/substrate/primitives/arithmetic/src/per_things.rs
+++ b/substrate/primitives/arithmetic/src/per_things.rs
@@ -639,8 +639,9 @@ macro_rules! implement_per_thing {
 					write!(fmt, "{:.2}% ({}/{})", pc, self.0, $max)
 				} else {
 					// A power of ten: calculate exact percent
-					let units = self.0 / ($max / 100);
-					let rest = self.0 % ($max / 100);
+					let divisor = $max / 100;
+					let units = self.0 / divisor;
+					let rest = self.0 % divisor;
 					write!(fmt, "{}", units)?;
 					if rest > 0 {
 						write!(fmt, ".")?;