diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -3591,11 +3591,19 @@
   DeclContext *Owner = FunctionTemplate->getDeclContext();
   if (FunctionTemplate->getFriendObjectKind())
     Owner = FunctionTemplate->getLexicalDeclContext();
+  FunctionDecl *FD = FunctionTemplate->getTemplatedDecl();
+  const FunctionDecl *FDFriend;
+  if (FD->getFriendObjectKind() == Decl::FriendObjectKind::FOK_None &&
+      FD->isDefined(FDFriend, true) &&
+      FDFriend->getFriendObjectKind() != Decl::FriendObjectKind::FOK_None) {
+    FD = const_cast<FunctionDecl *>(FDFriend);
+    Owner = FD->getDescribedFunctionTemplate()->getLexicalDeclContext();
+  }
   MultiLevelTemplateArgumentList SubstArgs(
       FunctionTemplate, CanonicalDeducedArgumentList->asArray(),
       /*Final=*/false);
   Specialization = cast_or_null<FunctionDecl>(
-      SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner, SubstArgs));
+      SubstDecl(FD, Owner, SubstArgs));
   if (!Specialization || Specialization->isInvalidDecl())
     return TDK_SubstitutionFailure;
 
diff --git a/clang/test/SemaTemplate/template-friend-definition-in-template.cpp b/clang/test/SemaTemplate/template-friend-definition-in-template.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/SemaTemplate/template-friend-definition-in-template.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// expected-no-diagnostics
+
+template <class F1> int foo(F1 X1);
+
+template <int A1> struct A {
+  template <class F2> friend int foo(F2 X2) {
+    return A1;
+  }
+};
+
+template struct A<1>;
+int main() { 
+  foo(1.0);
+}