diff --git a/crates/num-rug-adapter/src/lib.rs b/crates/num-rug-adapter/src/lib.rs
index 2f67b80d..6cb19918 100644
--- a/crates/num-rug-adapter/src/lib.rs
+++ b/crates/num-rug-adapter/src/lib.rs
@@ -118,6 +118,7 @@ impl Integer {
         Integer(num_integer::Integer::gcd(&self.0, &other.0))
     }
 
+    #[inline]
     pub fn count_ones(&self) -> Option<u32> {
         Some(self.0.to_u32_digits().1.iter().map(|&d| d.count_ones()).sum())
     }