diff --git a/src/executor/onnx_to_tensorrt.cc b/src/executor/onnx_to_tensorrt.cc
index e3a4ae868ce2..c557527f0b9b 100644
--- a/src/executor/onnx_to_tensorrt.cc
+++ b/src/executor/onnx_to_tensorrt.cc
@@ -100,8 +100,8 @@ nvinfer1::ICudaEngine* onnxToTrtCtx(
   }
 
   if ( !trt_parser->parse(onnx_model.c_str(), onnx_model.size()) ) {
-      int nerror = trt_parser->getNbErrors();
-      for ( int i=0; i < nerror; ++i ) {
+      size_t nerror = trt_parser->getNbErrors();
+      for ( size_t i=0; i < nerror; ++i ) {
         nvonnxparser::IParserError const* error = trt_parser->getError(i);
         if ( error->node() != -1 ) {
           ::ONNX_NAMESPACE::NodeProto const& node =
diff --git a/src/executor/trt_graph_executor.cc b/src/executor/trt_graph_executor.cc
index 65dbb29792e0..a5a054b85d3d 100644
--- a/src/executor/trt_graph_executor.cc
+++ b/src/executor/trt_graph_executor.cc
@@ -1,3 +1,5 @@
+#include <utility>
+
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -133,7 +135,7 @@ void TrtGraphExecutor::Init(nnvm::Symbol symbol,
   }
 
   auto trt_groups = GetTrtCompatibleSubsets(g, shared_buffer);
-  for (auto trt_group : trt_groups) {
+  for (const auto &trt_group : trt_groups) {
     if (trt_group.size() > 1) {
       g = ReplaceSubgraph(std::move(g), trt_group, shared_buffer);
       g = ReinitGraph(std::move(g), default_ctx, ctx_map, in_arg_ctxes, arg_grad_ctxes,
@@ -142,7 +144,6 @@ void TrtGraphExecutor::Init(nnvm::Symbol symbol,
     }
   }
 
-
   InitArguments(g.indexed_graph(), g.GetAttr<nnvm::ShapeVector>("shape"),
                 g.GetAttr<nnvm::DTypeVector>("dtype"),
                 g.GetAttr<StorageTypeVector>("storage_type"),
@@ -434,7 +435,7 @@ Executor *TrtGraphExecutor::TensorRTBind(nnvm::Symbol symbol,
                                          std::unordered_map<std::string, NDArray> *shared_buffer,
                                          Executor *shared_exec) {
   auto exec = new exec::TrtGraphExecutor();
-  exec->Init(symbol, default_ctx, group2ctx,
+  exec->Init(std::move(symbol), default_ctx, group2ctx,
              in_arg_ctxes, arg_grad_ctxes, aux_state_ctxes,
              arg_shape_map, arg_dtype_map, arg_stype_map,
              grad_req_types, param_names,
diff --git a/src/operator/contrib/nnvm_to_onnx-inl.h b/src/operator/contrib/nnvm_to_onnx-inl.h
index 58f88b051433..990b056b6a47 100644
--- a/src/operator/contrib/nnvm_to_onnx-inl.h
+++ b/src/operator/contrib/nnvm_to_onnx-inl.h
@@ -70,14 +70,14 @@ std::unordered_map<std::string, uint32_t> GetOutputLookup(const nnvm::IndexedGra
 void ConvertPlaceholder(
   const std::string& node_name,
   const std::unordered_map<std::string, TShape>& placeholder_shapes,
-  GraphProto* const graph_proto);
+  GraphProto* graph_proto);
 
-void ConvertConstant(GraphProto* const graph_proto,
+void ConvertConstant(GraphProto* graph_proto,
   const std::string& node_name,
-  std::unordered_map<std::string, NDArray>* const shared_buffer);
+  std::unordered_map<std::string, NDArray>* shared_buffer);
 
-void ConvertOutput(op::tensorrt::InferenceMap_t* const trt_output_map,
-                   GraphProto* const graph_proto,
+void ConvertOutput(op::tensorrt::InferenceMap_t* trt_output_map,
+                   GraphProto* graph_proto,
                    const std::unordered_map<std::string, uint32_t>::iterator& out_iter,
                    const std::string& node_name,
                    const nnvm::Graph& g,
@@ -135,7 +135,7 @@ void ConvertElementwiseAdd(NodeProto *node_proto,
 
 TRTParam ConvertNnvmGraphToOnnx(
     const nnvm::Graph &g,
-    std::unordered_map<std::string, NDArray> *const shared_buffer);
+    std::unordered_map<std::string, NDArray>* shared_buffer);
 
 static const std::unordered_map<std::string, ConverterFunction> converter_map = {
   {"Convolution", ConvertConvolution},
diff --git a/src/operator/contrib/nnvm_to_onnx.cc b/src/operator/contrib/nnvm_to_onnx.cc
index 902466614c7c..974eec10e2f7 100644
--- a/src/operator/contrib/nnvm_to_onnx.cc
+++ b/src/operator/contrib/nnvm_to_onnx.cc
@@ -60,10 +60,10 @@ namespace nnvm_to_onnx {
 op::TRTParam ConvertNnvmGraphToOnnx(
     const nnvm::Graph& g,
     std::unordered_map<std::string, NDArray>* const shared_buffer) {
-    op::TRTParam trt_param;
-    op::tensorrt::NameToIdx_t trt_input_map;
-    op::tensorrt::InferenceMap_t trt_output_map;
 
+  op::TRTParam trt_param;
+  op::tensorrt::NameToIdx_t trt_input_map;
+  op::tensorrt::InferenceMap_t trt_output_map;
   const nnvm::IndexedGraph& ig = g.indexed_graph();
   const auto& storage_types = g.GetAttr<StorageTypeVector>("storage_type");
   const auto& dtypes = g.GetAttr<DTypeVector>("dtype");
@@ -240,7 +240,7 @@ void ConvertPooling(NodeProto* node_proto, const NodeAttrs& attrs,
   AttributeProto* const kernel_shape = node_proto->add_attribute();
   kernel_shape->set_name("kernel_shape");
   kernel_shape->set_type(AttributeProto::INTS);
-  for (int kval : kernel) {
+  for (dim_t kval : kernel) {
     kernel_shape->add_ints(static_cast<int64>(kval));
   }
 
@@ -256,7 +256,7 @@ void ConvertPooling(NodeProto* node_proto, const NodeAttrs& attrs,
   AttributeProto* const strides = node_proto->add_attribute();
   strides->set_name("strides");
   strides->set_type(AttributeProto::INTS);
-  for (int kval : stride) {
+  for (dim_t kval : stride) {
     strides->add_ints(static_cast<int64>(kval));
   }