diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -381,6 +381,8 @@
 - Fix overly aggressive lifetime checks for parenthesized aggregate
   initialization.
   (`#61567 <https://github.com/llvm/llvm-project/issues/61567>`_)
+- Fix handling of constexpr dynamic memory allocations in template
+  arguments. (`#62462 <https://github.com/llvm/llvm-project/issues/62462>`_)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -15354,8 +15354,15 @@
   LValue LVal;
   LVal.set(Base);
 
-  if (!::EvaluateInPlace(Result.Val, Info, LVal, this) || Result.HasSideEffects)
-    return false;
+  {
+    // C++23 [intro.execution]/p5
+    // A full-expression is [...] a constant-expression
+    // So we need to make sure temporary objects are destroyed after having evaluating
+    // the expression (per C++23 [class.temporary]/p4).
+    FullExpressionRAII Scope(Info);
+    if (!::EvaluateInPlace(Result.Val, Info, LVal, this) || Result.HasSideEffects  || !Scope.destroy())
+      return false;
+  }
 
   if (!Info.discardCleanups())
     llvm_unreachable("Unhandled cleanup; missing full expression marker?");
diff --git a/clang/test/SemaCXX/cxx2a-constexpr-dynalloc.cpp b/clang/test/SemaCXX/cxx2a-constexpr-dynalloc.cpp
--- a/clang/test/SemaCXX/cxx2a-constexpr-dynalloc.cpp
+++ b/clang/test/SemaCXX/cxx2a-constexpr-dynalloc.cpp
@@ -215,3 +215,27 @@
   }
   static_assert(h());
 }
+
+namespace GH62462 {
+
+class string {
+public:
+  char *mem;
+  constexpr string() {
+    this->mem = new char(1);
+  }
+  constexpr ~string() {
+    delete this->mem;
+  }
+  constexpr unsigned size() const { return 4; }
+};
+
+
+template <unsigned N>
+void test() {};
+
+void f() {
+    test<string().size()>();
+}
+
+}