Index: cfe/trunk/lib/AST/ASTImporter.cpp
===================================================================
--- cfe/trunk/lib/AST/ASTImporter.cpp
+++ cfe/trunk/lib/AST/ASTImporter.cpp
@@ -1959,14 +1959,20 @@
   // but this particular declaration is not that definition, import the
   // definition and map to that.
   TagDecl *Definition = D->getDefinition();
-  if (Definition && Definition != D) {
+  if (Definition && Definition != D &&
+      // In contrast to a normal CXXRecordDecl, the implicit
+      // CXXRecordDecl of ClassTemplateSpecializationDecl is its redeclaration.
+      // The definition of the implicit CXXRecordDecl in this case is the
+      // ClassTemplateSpecializationDecl itself. Thus, we start with an extra
+      // condition in order to be able to import the implict Decl.
+      !D->isImplicit()) {
     Decl *ImportedDef = Importer.Import(Definition);
     if (!ImportedDef)
       return nullptr;
 
     return Importer.Imported(D, ImportedDef);
   }
-  
+
   // Import the major distinguishing characteristics of this record.
   DeclContext *DC, *LexicalDC;
   DeclarationName Name;
Index: cfe/trunk/unittests/AST/ASTImporterTest.cpp
===================================================================
--- cfe/trunk/unittests/AST/ASTImporterTest.cpp
+++ cfe/trunk/unittests/AST/ASTImporterTest.cpp
@@ -1363,6 +1363,22 @@
   Decl *From, *To;
   std::tie(From, To) = getImportedDecl(
       R"(
+      struct declToImport {
+      };
+      )",
+      Lang_CXX, "", Lang_CXX);
+
+  MatchVerifier<Decl> Verifier;
+  // Match the implicit Decl.
+  auto Matcher = cxxRecordDecl(has(cxxRecordDecl()));
+  ASSERT_TRUE(Verifier.match(From, Matcher));
+  EXPECT_TRUE(Verifier.match(To, Matcher));
+}
+
+TEST_P(ASTImporterTestBase, ShouldImportImplicitCXXRecordDeclOfClassTemplate) {
+  Decl *From, *To;
+  std::tie(From, To) = getImportedDecl(
+      R"(
       template <typename U>
       struct declToImport {
       };
@@ -1378,7 +1394,7 @@
 
 TEST_P(
     ASTImporterTestBase,
-    DISABLED_ShouldImportImplicitCXXRecordDeclOfClassTemplateSpecializationDecl) {
+    ShouldImportImplicitCXXRecordDeclOfClassTemplateSpecializationDecl) {
   Decl *From, *To;
   std::tie(From, To) = getImportedDecl(
       R"(