diff --git a/src/linux_rustix.rs b/src/linux_rustix.rs
index 30a6496c..babbad99 100644
--- a/src/linux_rustix.rs
+++ b/src/linux_rustix.rs
@@ -22,7 +22,7 @@ pub fn getrandom_inner(mut dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
                     .raw_os_error()
                     .wrapping_neg()
                     .try_into()
-                    .expect("Errno uses u16 internally");
+                    .map_err(|_| Error::UNEXPECTED)?;
                 return Err(Error::from_os_error(code));
             }
         }