Index: lib/AST/DeclBase.cpp
===================================================================
--- lib/AST/DeclBase.cpp
+++ lib/AST/DeclBase.cpp
@@ -1350,6 +1350,8 @@
           (D->NextInContextAndBits.getPointer() || D == LastDecl));
 }
 
+static bool shouldBeHidden(NamedDecl *D);
+
 void DeclContext::removeDecl(Decl *D) {
   assert(D->getLexicalDeclContext() == this &&
          "decl being removed from non-lexical context");
@@ -1372,7 +1374,7 @@
       }
     }
   }
-  
+
   // Mark that D is no longer in the decl chain.
   D->NextInContextAndBits.setPointer(nullptr);
 
@@ -1380,6 +1382,10 @@
   if (isa<NamedDecl>(D)) {
     auto *ND = cast<NamedDecl>(D);
 
+    // Do not try to remove the declaration if that is invisible to qualified
+    // lookup.  E.g. template specializations are skipped.
+    if (shouldBeHidden(ND)) return;
+
     // Remove only decls that have a name
     if (!ND->getDeclName()) return;
 
Index: unittests/AST/ASTImporterTest.cpp
===================================================================
--- unittests/AST/ASTImporterTest.cpp
+++ unittests/AST/ASTImporterTest.cpp
@@ -1764,5 +1764,38 @@
                  compoundStmt(has(callExpr(has(unresolvedMemberExpr())))))))));
 }
 
+struct DeclContextTest : ASTImporterTestBase {};
+
+TEST_P(DeclContextTest, removeDeclOfClassTemplateSpecialization) {
+  Decl *TU = getTuDecl(
+      R"(
+      namespace NS {
+
+      template <typename T>
+      struct S {};
+      template struct S<int>;
+
+      inline namespace INS {
+        template <typename T>
+        struct S {};
+        template struct S<int>;
+      }
+
+      }
+      )", Lang_CXX11, "input0.cc");
+  auto *NS = FirstDeclMatcher<NamespaceDecl>().match(
+      TU, namespaceDecl());
+  auto *Spec = FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
+      TU, classTemplateSpecializationDecl());
+  ASSERT_TRUE(NS->containsDecl(Spec));
+
+  NS->removeDecl(Spec);
+  EXPECT_FALSE(NS->containsDecl(Spec));
+}
+
+INSTANTIATE_TEST_CASE_P(
+    ParameterizedTests, DeclContextTest,
+    ::testing::Values(ArgVector(), ArgVector{"-fdelayed-template-parsing"}),);
+
 } // end namespace ast_matchers
 } // end namespace clang
Index: unittests/AST/MatchVerifier.h
===================================================================
--- unittests/AST/MatchVerifier.h
+++ unittests/AST/MatchVerifier.h
@@ -28,7 +28,7 @@
 namespace clang {
 namespace ast_matchers {
 
-enum Language { 
+enum Language {
     Lang_C,
     Lang_C89,
     Lang_CXX,