Index: lib/AST/DeclCXX.cpp
===================================================================
--- lib/AST/DeclCXX.cpp
+++ lib/AST/DeclCXX.cpp
@@ -1417,11 +1417,8 @@
                                           Context.getCanonicalType(ClassType));
 
   DeclContext::lookup_result R = lookup(Name);
-  if (R.empty())
-    return nullptr;
 
-  CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(R.front());
-  return Dtor;
+  return R.empty() ? nullptr : dyn_cast<CXXDestructorDecl>(R.front());
 }
 
 bool CXXRecordDecl::isAnyDestructorNoReturn() const {
Index: test/SemaTemplate/destructor-template.cpp
===================================================================
--- test/SemaTemplate/destructor-template.cpp
+++ test/SemaTemplate/destructor-template.cpp
@@ -86,3 +86,9 @@
   template<typename T> decltype(S<T>().~S()) f(); // expected-note {{candidate template ignored: couldn't infer template argument 'T'}}
   void g() { f(); } // expected-error {{no matching function for call to 'f'}}
 }
+
+class PR33189
+{
+  template <class T>
+  ~PR33189() { } // expected-error{{destructor cannot be declared as a template}}
+};