diff --git a/R-package/DESCRIPTION b/R-package/DESCRIPTION
index 6ca3a1ea44d8..d5cd1dd949eb 100644
--- a/R-package/DESCRIPTION
+++ b/R-package/DESCRIPTION
@@ -9,5 +9,5 @@ Description: MXNet is a deep learning framework designed for both efficiency and
 License: Apache-2.0
 URL: https://github.com/dmlc/mxnet
 BugReports: https://github.com/dmlc/mxnet/issues
-Imports: Rcpp (>= 0.11.1)
+Imports: methods, Rcpp (>= 0.11.1)
 LinkingTo: Rcpp
diff --git a/R-package/NAMESPACE b/R-package/NAMESPACE
index 8eb5798245ee..01b58a27fdc5 100644
--- a/R-package/NAMESPACE
+++ b/R-package/NAMESPACE
@@ -1,2 +1,3 @@
 exportPattern("^[[:alpha:]]+")
 import(Rcpp)
+import(methods)
diff --git a/R-package/R/ndarray.R b/R-package/R/ndarray.R
index 04f7ac50c788..098035c5ad94 100644
--- a/R-package/R/ndarray.R
+++ b/R-package/R/ndarray.R
@@ -1,8 +1,21 @@
+mx.nd.load <- function(filename) {
+  filename <- path.expand(filename)
+  mx.nd.internal.load(filename)
+}
+
+mx.nd.save <- function(ndarray, filename) {
+  filename <- path.expand(filename)
+  mx.nd.internal.save(ndarray, filename)
+}
+
+is.MXNDArray <- function(x)
+  inherits(x, "Rcpp_MXNDArray")
+
+
 #' NDArray
 #'
 #' Additional NDArray related operations
 init.ndarray.methods <- function() {
-  require(methods)
   setMethod("+", signature(e1 = "Rcpp_MXNDArray", e2 = "numeric"), function(e1, e2) {
     mx.nd.internal.plus.scalar(e1, e2)
   })
@@ -43,4 +56,3 @@ init.ndarray.methods <- function() {
     x$as.array()
   })
 }
-
diff --git a/R-package/R/base.R b/R-package/R/zzz.R
similarity index 95%
rename from R-package/R/base.R
rename to R-package/R/zzz.R
index 6c051f3d4209..7da79078d272 100644
--- a/R-package/R/base.R
+++ b/R-package/R/zzz.R
@@ -1,4 +1,3 @@
-require(methods)
 
 .onLoad <- function(libname, pkgname) {
   library.dynam("libmxnet", pkgname, libname, local=FALSE)
diff --git a/R-package/demo/basic_ndarray.R b/R-package/demo/basic_ndarray.R
index ded9cbe0213e..cd850d09670f 100644
--- a/R-package/demo/basic_ndarray.R
+++ b/R-package/demo/basic_ndarray.R
@@ -1,6 +1,4 @@
 require(mxnet)
-require(methods)
-
 
 x = as.array(c(1,2,3))
 mat = mx.nd.array(x, mx.cpu(0))
@@ -8,7 +6,7 @@ mat = mat + 1.0
 mat = mat + mat
 mat = mat - 5
 mat = 10 / mat
-mat = 7*mat
+mat = 7 * mat
 mat = 1 - mat + (2 * mat)/(mat + 0.5)
 as.array(mat)
 
diff --git a/R-package/src/ndarray.cc b/R-package/src/ndarray.cc
index b894937de231..ec6bdd4cd69e 100644
--- a/R-package/src/ndarray.cc
+++ b/R-package/src/ndarray.cc
@@ -157,7 +157,7 @@ void NDArray::Save(const Rcpp::RObject &sxptr,
     MX_CALL(MXNDArraySave(filename.c_str(), num_args,
                           dmlc::BeginPtr(handles),
                           dmlc::BeginPtr(keys)));
-  } else if (TYPEOF(sxptr) == EXTPTRSXP) {
+  } else if (TYPEOF(sxptr) == EXTPTRSXP) { // TODO this line is wrong??
     MX_CALL(MXNDArraySave(filename.c_str(), 1,
                           &(NDArray::XPtr(sxptr)->handle_), nullptr));
   } else {
@@ -220,8 +220,9 @@ void NDArray::InitRcppModule() {
   using namespace Rcpp;  // NOLINT(*)
   class_<NDArray>("MXNDArray")
       .method("as.array", &NDArray::AsNumericVector);
-  function("mx.nd.load", &NDArray::Load);
-  function("mx.nd.save", &NDArray::Save);
+  // don't call load/save directly, let R provides the completed file path first
+  function("mx.nd.internal.load", &NDArray::Load);
+  function("mx.nd.internal.save", &NDArray::Save);
   function("mx.nd.array", &NDArray::Array);
 }
 
diff --git a/R-package/src/ndarray.h b/R-package/src/ndarray.h
index 21371f8ba57b..5dcd0ae79514 100644
--- a/R-package/src/ndarray.h
+++ b/R-package/src/ndarray.h
@@ -170,7 +170,7 @@ class NDArrayFunction : public ::Rcpp::CppFunction {
 }  // namespace mxnet
 
 
-RCPP_EXPOSED_CLASS_NODECL(::mxnet::R::NDArray);
+RCPP_EXPOSED_CLASS_NODECL(::mxnet::R::NDArray)
 
 namespace mxnet {
 namespace R {