diff --git a/src/index/id_map.rs b/src/index/id_map.rs
index 13aa777432..1e94961143 100644
--- a/src/index/id_map.rs
+++ b/src/index/id_map.rs
@@ -360,7 +360,6 @@ mod tests {
         let mut index = index_factory(4, "Flat", MetricType::L2).unwrap();
         let mut id_index = IdMap::new(index).unwrap();
         let some_data = &[2.3_f32, 0.0, -1., 1., 1., 1., 1., 4.5, 2.3, 7.6, 1., 2.2];
-        println!("{}", some_data.len());
 
         let ids = &[4, 8, 12];
 
@@ -370,7 +369,6 @@ mod tests {
         let id_sel = IdSelector::batch(&[4, 12]).ok().unwrap();
 
         id_index.remove_ids(&id_sel).unwrap();
-        println!("{}", id_index.ntotal());
         assert_eq!(id_index.ntotal(), 1);
     }
 }
diff --git a/src/macros.rs b/src/macros.rs
index 5d451e8193..fcbfa58e1c 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -109,7 +109,7 @@ macro_rules! impl_native_index {
                 }
             }
 
-            fn remove_ids(&mut self, sel: &IdSelector) -> Result<(i64)> {
+            fn remove_ids(&mut self, sel: &IdSelector) -> Result<i64> {
                 unsafe {
                     let mut n_removed = 0;
                     faiss_try!(faiss_Index_remove_ids(
diff --git a/src/selector.rs b/src/selector.rs
index 81618a187a..37ef36d474 100644
--- a/src/selector.rs
+++ b/src/selector.rs
@@ -2,6 +2,7 @@
 use error::Result;
 use faiss_sys::*;
 use index::Idx;
+use std::os::raw::c_long;
 use std::ptr;
 
 /// Abstraction over IDSelectorRange and IDSelectorBatch
@@ -22,10 +23,10 @@ impl IdSelector {
 
     /// Create new batch selector
     pub fn batch(indices: &[Idx]) -> Result<Self> {
-        let n = indices.len() as i64;
+        let n = indices.len() as c_long;
         let mut p_sel = ptr::null_mut();
         unsafe {
-            faiss_try!(faiss_IDSelectorBatch_new(&mut p_sel, n, &indices[0]));
+            faiss_try!(faiss_IDSelectorBatch_new(&mut p_sel, n, indices.as_ptr()));
         };
         Ok(IdSelector { inner: p_sel as *mut _})
     }