diff --git a/.gitmodules b/.gitmodules
index 8df83c3ec..1f52fff57 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +1,7 @@
 [submodule "dmlc-core"]
 	path = dmlc-core
 	url = https://github.com/dmlc/dmlc-core
+	branch = main
 [submodule "cub"]
 	path = cub
 	url = https://github.com/NVlabs/cub
diff --git a/dmlc-core b/dmlc-core
index 5df8305fe..f0ff31467 160000
--- a/dmlc-core
+++ b/dmlc-core
@@ -1 +1 @@
-Subproject commit 5df8305fe699d3b503d10c60a231ab0223142407
+Subproject commit f0ff3146705e27ac2b1e6081fa0983a8a6fda72d
diff --git a/include/xgboost/parameter.h b/include/xgboost/parameter.h
index 3186651ed..fca05cef4 100644
--- a/include/xgboost/parameter.h
+++ b/include/xgboost/parameter.h
@@ -87,14 +87,11 @@ struct XGBoostParameter : public dmlc::Parameter<Type> {
 
  public:
   template <typename Container>
-  Args UpdateAllowUnknown(Container const& kwargs, bool* out_changed = nullptr) {
+  Args UpdateAllowUnknown(Container const& kwargs) {
     if (initialised_) {
-      return dmlc::Parameter<Type>::UpdateAllowUnknown(kwargs, out_changed);
+      return dmlc::Parameter<Type>::UpdateAllowUnknown(kwargs);
     } else {
       auto unknown = dmlc::Parameter<Type>::InitAllowUnknown(kwargs);
-      if (out_changed) {
-        *out_changed = true;
-      }
       initialised_ = true;
       return unknown;
     }