diff --git a/src/c_types.rs b/src/c_types.rs
index 7234c03..b840c37 100644
--- a/src/c_types.rs
+++ b/src/c_types.rs
@@ -43,7 +43,7 @@ pub type CShort = i16;
 pub type CUShort = u16;
 pub type CInt = i32;
 pub type CUInt = u32;
-pub type CLongLong = u64;
+pub type CLongLong = i64;
 pub type CULongLong = u64;
 pub type CFloat = f32;
 pub type CDouble = f64;