diff --git a/include/xgboost/json.h b/include/xgboost/json.h
index 4c4bafb1a..68a8a6712 100644
--- a/include/xgboost/json.h
+++ b/include/xgboost/json.h
@@ -250,7 +250,7 @@ class JsonNull : public Value {
  public:
   JsonNull() : Value(ValueKind::kNull) {}
   JsonNull(std::nullptr_t) : Value(ValueKind::kNull) {}  // NOLINT
-  JsonNull(JsonNull&& that) : Value(ValueKind::kNull) {}
+  JsonNull(JsonNull&&) : Value(ValueKind::kNull) {}
 
   void Save(JsonWriter* writer) override;
 
diff --git a/include/xgboost/metric.h b/include/xgboost/metric.h
index faca15504..b1d69b99a 100644
--- a/include/xgboost/metric.h
+++ b/include/xgboost/metric.h
@@ -34,7 +34,7 @@ class Metric : public Configurable {
    * \param args arguments to the objective function.
    */
   virtual void Configure(
-      const std::vector<std::pair<std::string, std::string> >& args) {}
+      const std::vector<std::pair<std::string, std::string> >&) {}
   /*!
    * \brief Load configuration from JSON object
    * By default, metric has no internal configuration;
diff --git a/src/tree/updater_histmaker.cc b/src/tree/updater_histmaker.cc
index c4fdbe3c0..6deb42113 100644
--- a/src/tree/updater_histmaker.cc
+++ b/src/tree/updater_histmaker.cc
@@ -146,7 +146,7 @@ class HistMaker: public BaseMaker {
                                   const std::vector <bst_feature_t> &fset,
                                   const RegTree &tree) = 0;
   // initialize the current working set of features in this round
-  virtual void InitWorkSet(DMatrix *p_fmat,
+  virtual void InitWorkSet(DMatrix *,
                            const RegTree &tree,
                            std::vector<bst_feature_t> *p_fset) {
     p_fset->resize(tree.param.num_feature);
diff --git a/src/tree/updater_quantile_hist.cc b/src/tree/updater_quantile_hist.cc
index 61cc0f562..f22e0d5cd 100644
--- a/src/tree/updater_quantile_hist.cc
+++ b/src/tree/updater_quantile_hist.cc
@@ -127,12 +127,12 @@ bool QuantileHistMaker::UpdatePredictionCache(
 
 template <typename GradientSumT>
 void BatchHistSynchronizer<GradientSumT>::SyncHistograms(BuilderT *builder,
-                                                         int starting_index,
-                                                         int sync_count,
+                                                         int,
+                                                         int,
                                                          RegTree *p_tree) {
   builder->builder_monitor_.Start("SyncHistograms");
   const size_t nbins = builder->hist_builder_.GetNumBins();
-  common::BlockedSpace2d space(builder->nodes_for_explicit_hist_build_.size(), [&](size_t node) {
+  common::BlockedSpace2d space(builder->nodes_for_explicit_hist_build_.size(), [&](size_t) {
     return nbins;
   }, 1024);
 
@@ -159,7 +159,7 @@ void DistributedHistSynchronizer<GradientSumT>::SyncHistograms(BuilderT* builder
                                                  RegTree *p_tree) {
   builder->builder_monitor_.Start("SyncHistograms");
   const size_t nbins = builder->hist_builder_.GetNumBins();
-  common::BlockedSpace2d space(builder->nodes_for_explicit_hist_build_.size(), [&](size_t node) {
+  common::BlockedSpace2d space(builder->nodes_for_explicit_hist_build_.size(), [&](size_t) {
     return nbins;
   }, 1024);
   common::ParallelFor2d(space, builder->nthread_, [&](size_t node, common::Range1d r) {
@@ -188,7 +188,7 @@ void DistributedHistSynchronizer<GradientSumT>::SyncHistograms(BuilderT* builder
 
   ParallelSubtractionHist(builder, space, builder->nodes_for_explicit_hist_build_, p_tree);
 
-  common::BlockedSpace2d space2(builder->nodes_for_subtraction_trick_.size(), [&](size_t node) {
+  common::BlockedSpace2d space2(builder->nodes_for_subtraction_trick_.size(), [&](size_t) {
     return nbins;
   }, 1024);
   ParallelSubtractionHist(builder, space2, builder->nodes_for_subtraction_trick_, p_tree);
@@ -219,7 +219,7 @@ template <typename GradientSumT>
 void BatchHistRowsAdder<GradientSumT>::AddHistRows(BuilderT *builder,
                                                    int *starting_index,
                                                    int *sync_count,
-                                                   RegTree *p_tree) {
+                                                   RegTree *) {
   builder->builder_monitor_.Start("AddHistRows");
 
   for (auto const& entry : builder->nodes_for_explicit_hist_build_) {