diff --git lib/Sema/SemaTemplateInstantiateDecl.cpp lib/Sema/SemaTemplateInstantiateDecl.cpp
index 1df0701..6980769 100644
--- lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1265,11 +1265,19 @@ Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
   // DR1484 clarifies that the members of a local class are instantiated as part
   // of the instantiation of their enclosing entity.
   if (D->isCompleteDefinition() && D->isLocalClass()) {
+    Sema::SavePendingLocalImplicitInstantiationsRAII
+        SavedPendingLocalImplicitInstantiations(SemaRef);
+
     SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
                              TSK_ImplicitInstantiation,
                              /*Complain=*/true);
+
     SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
                                     TSK_ImplicitInstantiation);
+
+    // This class may have local implicit instantiations that need to be
+    // performed within this scope.
+    SemaRef.PerformPendingInstantiations(/*LocalOnly=*/true);
   }
 
   SemaRef.DiagnoseUnusedNestedTypedefs(Record);
diff --git test/SemaTemplate/instantiate-local-class.cpp test/SemaTemplate/instantiate-local-class.cpp
index c9897b9..a945c01 100644
--- test/SemaTemplate/instantiate-local-class.cpp
+++ test/SemaTemplate/instantiate-local-class.cpp
@@ -194,3 +194,16 @@ struct B {
   void f() { F<int>(); }
 };
 }
+
+namespace PR20625 {
+template <typename T>
+void f() {
+  struct N {
+    static constexpr int get() { return 42; }
+  };
+  constexpr int n = N::get();
+  static_assert(n == 42, "n == 42");
+}
+
+void g() { f<void>(); }
+}