diff --git a/src/common/cuda_rt_utils.cc b/src/common/cuda_rt_utils.cc
index 66de8dd4d311..d17e17d820f9 100644
--- a/src/common/cuda_rt_utils.cc
+++ b/src/common/cuda_rt_utils.cc
@@ -108,6 +108,8 @@ bool SupportsPageableMem() { return false; }
 
 bool SupportsAts() { return false; }
 
+[[nodiscard]] std::size_t TotalMemory() { return 0; }
+
 void CheckComputeCapability() {}
 
 void SetDevice(std::int32_t device) {
diff --git a/src/data/extmem_quantile_dmatrix.cc b/src/data/extmem_quantile_dmatrix.cc
index 9026411eec85..9bdd0dec1eea 100644
--- a/src/data/extmem_quantile_dmatrix.cc
+++ b/src/data/extmem_quantile_dmatrix.cc
@@ -134,7 +134,7 @@ BatchSet<GHistIndexMatrix> ExtMemQuantileDMatrix::GetGradientIndex(Context const
 #if !defined(XGBOOST_USE_CUDA)
 void ExtMemQuantileDMatrix::InitFromCUDA(
     Context const *, std::shared_ptr<DataIterProxy<DataIterResetCallback, XGDMatrixCallbackNext>>,
-    DMatrixHandle, BatchParam const &, float, std::shared_ptr<DMatrix>) {
+    DMatrixHandle, BatchParam const &, std::shared_ptr<DMatrix>, ExtMemConfig const &) {
   common::AssertGPUSupport();
 }