Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -17057,11 +17057,12 @@
           PointOfInstantiation = Loc;
         }
 
+        const bool isLocalClass =
+            isa<CXXRecordDecl>(Func->getDeclContext()) &&
+            cast<CXXRecordDecl>(Func->getDeclContext())->isLocalClass();
         if (FirstInstantiation || TSK != TSK_ImplicitInstantiation ||
-            Func->isConstexpr()) {
-          if (isa<CXXRecordDecl>(Func->getDeclContext()) &&
-              cast<CXXRecordDecl>(Func->getDeclContext())->isLocalClass() &&
-              CodeSynthesisContexts.size())
+            (!isLocalClass && Func->isConstexpr())) {
+          if (isLocalClass && CodeSynthesisContexts.size())
             PendingLocalImplicitInstantiations.push_back(
                 std::make_pair(Func, PointOfInstantiation));
           else if (Func->isConstexpr())
Index: clang/test/SemaTemplate/instantiate-local-class.cpp
===================================================================
--- clang/test/SemaTemplate/instantiate-local-class.cpp
+++ clang/test/SemaTemplate/instantiate-local-class.cpp
@@ -504,3 +504,24 @@
   }
   template void f<int>();
 }
+
+namespace PR48839 {
+template <typename T>
+void construct() {
+  T(0);
+}
+
+template <typename T>
+void tester() {
+  struct d {
+    void test() {
+      construct<d>();
+    }
+    constexpr d(T b) : a(b) {}
+
+    T a;
+  };
+}
+
+void g() { tester<int>(); }
+} // namespace PR48839