diff --git a/src/header/signal/mod.rs b/src/header/signal/mod.rs
index 04f603c64b9775dcaca69dbdba79f703fd2072a5..49db58cbc2517959125551c2c41ffb87c07f5441 100644
--- a/src/header/signal/mod.rs
+++ b/src/header/signal/mod.rs
@@ -23,7 +23,7 @@ type SigSet = BitSet<[c_ulong; 1]>;
 
 pub const SIG_DFL: usize = 0;
 pub const SIG_IGN: usize = 1;
-pub const SIG_ERR: usize = !0;
+pub const SIG_ERR: isize = -1;
 
 pub const SIG_BLOCK: c_int = 0;
 pub const SIG_UNBLOCK: c_int = 1;