diff --git a/src/ffi2/objectabstract.rs b/src/ffi2/objectabstract.rs
index 96ef08ea..c43d7dfb 100644
--- a/src/ffi2/objectabstract.rs
+++ b/src/ffi2/objectabstract.rs
@@ -295,15 +295,15 @@ pub unsafe fn PyMapping_DelItem(o : *mut PyObject, key : *mut PyObject) -> c_int
 
 #[inline]
 pub unsafe fn PyMapping_Keys(o : *mut PyObject) -> *mut PyObject {
-    PyObject_CallMethod(o, "keys\0".as_ptr() as *mut i8, ptr::null_mut())
+    PyObject_CallMethod(o, "keys\0".as_ptr() as *mut u8, ptr::null_mut())
 }
 
 #[inline]
 pub unsafe fn PyMapping_Values(o : *mut PyObject) -> *mut PyObject {
-    PyObject_CallMethod(o, "values\0".as_ptr() as *mut i8, ptr::null_mut())
+    PyObject_CallMethod(o, "values\0".as_ptr() as *mut u8, ptr::null_mut())
 }
 
 #[inline]
 pub unsafe fn PyMapping_Items(o : *mut PyObject) -> *mut PyObject {
-    PyObject_CallMethod(o, "items\0".as_ptr() as *mut i8, ptr::null_mut())
+    PyObject_CallMethod(o, "items\0".as_ptr() as *mut u8, ptr::null_mut())
 }