diff --git a/src/unix/aix/mod.rs b/src/unix/aix/mod.rs
index 0fc923d6072f0..b3ce43a3722d1 100644
--- a/src/unix/aix/mod.rs
+++ b/src/unix/aix/mod.rs
@@ -1,4 +1,4 @@
-pub type c_char = i8;
+pub type c_char = u8;
 pub type caddr_t = *mut ::c_char;
 pub type clockid_t = ::c_longlong;
 pub type blkcnt_t = ::c_long;