diff --git a/librocksdb-sys/tests/ffi.rs b/librocksdb-sys/tests/ffi.rs
index 87f1519..c6718a9 100644
--- a/librocksdb-sys/tests/ffi.rs
+++ b/librocksdb-sys/tests/ffi.rs
@@ -716,7 +716,7 @@ fn ffi() {
 
         StartPhase("approximate_sizes");
         {
-            let mut sizes: [uint64_t; 2] = [0, 0];
+            let mut sizes: [u64; 2] = [0, 0];
             let start: [*const c_char; 2] = [cstrp!("a"), cstrp!("k00000000000000010000")];
             let start_len: [size_t; 2] = [1, 21];
             let limit: [*const c_char; 2] = [cstrp!("k00000000000000010000"), cstrp!("z")];
diff --git a/src/backup.rs b/src/backup.rs
index ccb9d18..bc35642 100644
--- a/src/backup.rs
+++ b/src/backup.rs
@@ -16,7 +16,7 @@
 use ffi;
 use {Error, DB};
 
-use libc::{c_int, uint32_t};
+use libc::c_int;
 use std::ffi::CString;
 use std::path::Path;
 
@@ -73,7 +73,7 @@ impl BackupEngine {
         unsafe {
             ffi_try!(ffi::rocksdb_backup_engine_purge_old_backups(
                 self.inner,
-                num_backups_to_keep as uint32_t,
+                num_backups_to_keep as u32,
             ));
             Ok(())
         }
diff --git a/src/db_options.rs b/src/db_options.rs
index 0a9b4f7..1e72037 100644
--- a/src/db_options.rs
+++ b/src/db_options.rs
@@ -16,7 +16,7 @@ use std::ffi::{CStr, CString};
 use std::mem;
 use std::path::Path;
 
-use libc::{self, c_int, c_uchar, c_uint, c_void, size_t, uint64_t};
+use libc::{self, c_int, c_uchar, c_uint, c_void, size_t};
 
 use compaction_filter::{self, filter_callback, CompactionFilterCallback, CompactionFilterFn};
 use comparator::{self, ComparatorCallback, CompareFn};
@@ -162,7 +162,7 @@ impl Options {
         unsafe {
             ffi::rocksdb_options_optimize_level_style_compaction(
                 self.inner,
-                memtable_memory_budget as uint64_t,
+                memtable_memory_budget as u64,
             );
         }
     }