diff --git a/src/tree/updater_gpu_hist.cu b/src/tree/updater_gpu_hist.cu
index e899925cd146..8d0efd41872e 100644
--- a/src/tree/updater_gpu_hist.cu
+++ b/src/tree/updater_gpu_hist.cu
@@ -193,7 +193,7 @@ struct GPUHistMakerDevice {
   std::unique_ptr<GradientBasedSampler> sampler;
 
   std::unique_ptr<FeatureGroups> feature_groups;
-  // Storing split categories for 1 node.
+  // Storing split categories for last node.
   dh::caching_device_vector<uint32_t> node_categories;
 
   GPUHistMakerDevice(int _device_id,
@@ -605,10 +605,7 @@ struct GPUHistMakerDevice {
       std::vector<uint32_t> split_cats(LBitField32::ComputeStorageSize(std::max(cat+1, 1)));
       LBitField32 cats_bits(split_cats);
       cats_bits.Set(cat);
-      node_categories.resize(split_cats.size());
-      dh::safe_cuda(cudaMemcpyAsync(
-          node_categories.data().get(), split_cats.data(),
-          split_cats.size() * sizeof(uint32_t), cudaMemcpyHostToDevice));
+      dh::CopyToD(split_cats, &node_categories);
       tree.ExpandCategorical(
           candidate.nid, candidate.split.findex, split_cats,
           candidate.split.dir == kLeftDir, base_weight, left_weight,
diff --git a/tests/cpp/tree/test_gpu_hist.cu b/tests/cpp/tree/test_gpu_hist.cu
index 2c4b6be34dd6..4a96cb2877a3 100644
--- a/tests/cpp/tree/test_gpu_hist.cu
+++ b/tests/cpp/tree/test_gpu_hist.cu
@@ -130,6 +130,47 @@ TEST(GpuHist, BuildHistSharedMem) {
   TestBuildHist<GradientPair>(true);
 }
 
+TEST(GpuHist, ApplySplit) {
+  RegTree tree;
+  ExpandEntry candidate;
+  candidate.left_weight = 1.0f;
+  candidate.right_weight = 2.0f;
+  candidate.base_weight = 3.0f;
+  candidate.split.is_cat = true;
+  candidate.split.fvalue = 1.0f;  // at cat 1
+
+  size_t n_rows = 10;
+  size_t n_cols = 10;
+
+  auto m = RandomDataGenerator{n_rows, n_cols, 0}.GenerateDMatrix(true);
+  GenericParameter p;
+  p.InitAllowUnknown(Args{});
+
+  TrainParam tparam;
+  tparam.InitAllowUnknown(Args{});
+  BatchParam bparam;
+  bparam.gpu_id = 0;
+  bparam.max_bin = 3;
+  bparam.gpu_page_size = 0;
+
+  for (auto& ellpack : m->GetBatches<EllpackPage>(bparam)){
+    auto impl = ellpack.Impl();
+    HostDeviceVector<FeatureType> feature_types(10, FeatureType::kCategorical);
+    feature_types.SetDevice(bparam.gpu_id);
+    tree::GPUHistMakerDevice<GradientPairPrecise> updater(
+        0, impl, feature_types.ConstDeviceSpan(), n_rows, tparam, 0, n_cols, true, bparam);
+    updater.ApplySplit(candidate, &tree);
+
+    ASSERT_EQ(tree.GetSplitTypes().size(), 3);
+    ASSERT_EQ(tree.GetSplitTypes()[0], FeatureType::kCategorical);
+    ASSERT_EQ(tree.GetSplitCategories().size(), 1);
+    uint32_t bits = 1u << 30;  // bits: 0, 1, 0, 0, 0, ..., 0
+    ASSERT_EQ(tree.GetSplitCategories().back(), bits);
+
+    ASSERT_EQ(updater.node_categories.size(), 1);
+  }
+}
+
 HistogramCutsWrapper GetHostCutMatrix () {
   HistogramCutsWrapper cmat;
   cmat.SetPtrs({0, 3, 6, 9, 12, 15, 18, 21, 24});