Index: clang/lib/AST/Interp/ByteCodeExprGen.cpp
===================================================================
--- clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -1376,7 +1376,7 @@
   if (const auto CtorExpr = dyn_cast<CXXConstructExpr>(Initializer)) {
     const Function *Func = getFunction(CtorExpr->getConstructor());
 
-    if (!Func || !Func->isConstexpr())
+    if (!Func)
       return false;
 
     // The This pointer is already on the stack because this is an initializer,
Index: clang/test/AST/Interp/cxx20.cpp
===================================================================
--- clang/test/AST/Interp/cxx20.cpp
+++ clang/test/AST/Interp/cxx20.cpp
@@ -207,13 +207,15 @@
                       // ref-note {{declared const here}}
     int a;
   public:
-    constexpr Foo() {
+    constexpr Foo() { // expected-note {{declared here}}
       this->a = 10;
       T = 13; // expected-error {{cannot assign to non-static data member 'T' with const-qualified type}} \
               // ref-error {{cannot assign to non-static data member 'T' with const-qualified type}}
     }
   };
   constexpr Foo F; // expected-error {{must be initialized by a constant expression}} \
+                   // FIXME: The following note is wrong.
+                   // expected-note {{undefined constructor 'Foo' cannot be used in a constant expression}} \
                    // ref-error {{must be initialized by a constant expression}}
 
 
Index: clang/test/AST/Interp/records.cpp
===================================================================
--- clang/test/AST/Interp/records.cpp
+++ clang/test/AST/Interp/records.cpp
@@ -308,7 +308,7 @@
 };
 
 namespace DeriveFailures {
-  struct Base { // ref-note 2{{declared here}}
+  struct Base { // ref-note 2{{declared here}} expected-note {{declared here}}
     int Val;
   };
 
@@ -316,13 +316,15 @@
     int OtherVal;
 
     constexpr Derived(int i) : OtherVal(i) {} // ref-error {{never produces a constant expression}} \
-                                              // ref-note 2{{non-constexpr constructor 'Base' cannot be used in a constant expression}}
+                                              // ref-note 2{{non-constexpr constructor 'Base' cannot be used in a constant expression}} \
+                                              // expected-note {{non-constexpr constructor 'Base' cannot be used in a constant expression}}
   };
 
   constexpr Derived D(12); // ref-error {{must be initialized by a constant expression}} \
                            // ref-note {{in call to 'Derived(12)'}} \
                            // ref-note {{declared here}} \
-                           // expected-error {{must be initialized by a constant expression}}
+                           // expected-error {{must be initialized by a constant expression}} \
+                           // expected-note {{in call to 'Derived(12)'}}
   static_assert(D.Val == 0, ""); // ref-error {{not an integral constant expression}} \
                                  // ref-note {{initializer of 'D' is not a constant expression}} \
                                  // expected-error {{not an integral constant expression}} \
@@ -348,7 +350,7 @@
   };
 
   struct YetAnotherDerived : YetAnotherBase {
-    using YetAnotherBase::YetAnotherBase; //ref-note {{declared here}}
+    using YetAnotherBase::YetAnotherBase; //ref-note {{declared here}} expected-note {{declared here}}
     int OtherVal;
 
     constexpr bool doit() const { return Val == OtherVal; }
@@ -356,8 +358,8 @@
 
   constexpr YetAnotherDerived Oops(0); // ref-error {{must be initialized by a constant expression}} \
                                        // ref-note {{constructor inherited from base class 'YetAnotherBase' cannot be used in a constant expression}} \
-                                       // expected-error {{must be initialized by a constant expression}}
-                                       // FIXME: Missing reason for rejection.
+                                       // expected-error {{must be initialized by a constant expression}} \
+                                       // expected-note {{constructor inherited from base class 'YetAnotherBase' cannot be used in a constant expression}}
 };
 
 namespace EmptyCtor {