diff --git a/src/unix/redox/mod.rs b/src/unix/redox/mod.rs
index f9f565edb7a1e..daba387093a9a 100644
--- a/src/unix/redox/mod.rs
+++ b/src/unix/redox/mod.rs
@@ -153,7 +153,7 @@ s! {
     #[allow(unpredictable_function_pointer_comparisons)]
     pub struct sigaction {
         pub sa_sigaction: crate::sighandler_t,
-        pub sa_flags: c_ulong,
+        pub sa_flags: c_int,
         pub sa_restorer: Option<extern "C" fn()>,
         pub sa_mask: crate::sigset_t,
     }