diff --git a/src/libgetopt.rs b/src/libgetopt.rs
index ee8cafa..8064c81 100644
--- a/src/libgetopt.rs
+++ b/src/libgetopt.rs
@@ -88,7 +88,7 @@ impl GetOpt for Vec<String> {
 
 		/* god knows what this does */
 		let boxed = Box::into_raw(c_strings.into_boxed_slice());
-		let argv = boxed as *const *mut i8;
+		let argv = boxed as *const *mut c_char;
 
 		/* operations are separated out so that everything lives long enough */
         let opts = CString::new(optstring).unwrap().into_raw();