diff --git a/Cargo.toml b/Cargo.toml
index 49f5797354d08..df298044fd834 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ license = "Unlicense/MIT"
 name = "memchr"
 
 [dependencies]
-libc = "0.2"
+libc = "0.2.4"
 
 [dev-dependencies]
 quickcheck = "0.2"
diff --git a/src/lib.rs b/src/lib.rs
index 2475bcb6a2af5..342e55eaf7a27 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -84,7 +84,7 @@ pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize> {
         // GNU's memrchr() will - unlike memchr() - error if haystack is empty.
         if haystack.is_empty() {return None}
         let p = unsafe {
-            ffi::memrchr(
+            libc::memrchr(
                 haystack.as_ptr() as *const c_void,
                 needle as c_int,
                 haystack.len() as size_t)
@@ -253,15 +253,6 @@ mod fallback {
     }
 }
 
-#[cfg(target_os = "linux")]
-mod ffi {
-    use libc::c_void;
-    use libc::{c_int, size_t};
-    extern {
-        pub fn memrchr(cx: *const c_void, c: c_int, n: size_t) -> *mut c_void;
-    }
-}
-
 #[cfg(test)]
 mod tests {
     extern crate quickcheck;