diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -3417,6 +3417,29 @@
 }
 
 TEST_P(ASTImporterOptionSpecificTestBase,
+       ClassTemplateFriendDecl) {
+  auto Code =
+      R"(
+      template <class T> class X {  friend T; };
+      struct Y {};
+      template class X<Y>;
+    )";
+  Decl *ToTU = getToTuDecl(Code, Lang_CXX11);
+  Decl *FromTU = getTuDecl(Code, Lang_CXX11);
+  auto *FromSpec =
+      FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
+          FromTU, classTemplateSpecializationDecl());
+  auto *ToSpec =
+      FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
+          ToTU, classTemplateSpecializationDecl());
+
+  auto *ImportedSpec = Import(FromSpec, Lang_CXX11);
+  EXPECT_EQ(ImportedSpec, ToSpec);
+  EXPECT_EQ(1u, DeclCounter<ClassTemplateSpecializationDecl>().match(
+                    ToTU, classTemplateSpecializationDecl()));
+}
+
+TEST_P(ASTImporterOptionSpecificTestBase,
        ClassTemplatePartialSpecializationsShouldNotBeDuplicated) {
   auto Code =
       R"(