diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -9188,6 +9188,7 @@
             << Name << RemoveRange
             << FixItHint::CreateRemoval(RemoveRange)
             << FixItHint::CreateInsertion(InsertLoc, "<>");
+          NewFD->setInvalidDecl();
         }
       }
     } else {
diff --git a/clang/test/CXX/temp/temp.spec/temp.expl.spec/p20.cpp b/clang/test/CXX/temp/temp.spec/temp.expl.spec/p20.cpp
--- a/clang/test/CXX/temp/temp.spec/temp.expl.spec/p20.cpp
+++ b/clang/test/CXX/temp/temp.spec/temp.expl.spec/p20.cpp
@@ -13,11 +13,16 @@
   friend class A<float>; // okay
 };
 
+template<typename T>
 struct PR41792 {
   // expected-error@+1{{cannot declare an explicit specialization in a friend}}
-  template <> friend void f<>(int);
+  template <> friend void f<>(int) {}
 
   // expected-error@+2{{template specialization declaration cannot be a friend}}
   // expected-error@+1{{too few template arguments for class template 'A'}}
   template <> friend class A<>;
 };
+
+void foo(void) {
+    PR41792<int> a;
+}