diff --git a/src/mlpack/methods/neighbor_search/ns_model.hpp b/src/mlpack/methods/neighbor_search/ns_model.hpp
index db3331a3e4..711d640703 100644
--- a/src/mlpack/methods/neighbor_search/ns_model.hpp
+++ b/src/mlpack/methods/neighbor_search/ns_model.hpp
@@ -69,7 +69,11 @@ class MonoSearchVisitor : public boost::static_visitor<void>
 
   MonoSearchVisitor(const size_t k,
                     arma::Mat<size_t>& neighbors,
-                    arma::mat& distances);
+                    arma::mat& distances) :
+      k(k),
+      neighbors(neighbors),
+      distances(distances)
+  {};
 };
 
 /**
diff --git a/src/mlpack/methods/neighbor_search/ns_model_impl.hpp b/src/mlpack/methods/neighbor_search/ns_model_impl.hpp
index 075306bece..da8ab07f98 100644
--- a/src/mlpack/methods/neighbor_search/ns_model_impl.hpp
+++ b/src/mlpack/methods/neighbor_search/ns_model_impl.hpp
@@ -18,15 +18,6 @@
 namespace mlpack {
 namespace neighbor {
 
-//! Save parameters for monochromatic neighbor search.
-MonoSearchVisitor::MonoSearchVisitor(const size_t k,
-                                     arma::Mat<size_t>& neighbors,
-                                     arma::mat& distances) :
-    k(k),
-    neighbors(neighbors),
-    distances(distances)
-{}
-
 //! Monochromatic neighbor search on the given NSType instance.
 template<typename NSType>
 void MonoSearchVisitor::operator()(NSType *ns) const