diff --git a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
index 480da46713c9..26ec8a3a860e 100644
--- a/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/queue/queue.cons/deduct.pass.cpp
@@ -9,8 +9,10 @@
 
 // <queue>
 // UNSUPPORTED: c++98, c++03, c++11, c++14
+// UNSUPPORTED: clang-5
 // UNSUPPORTED: libcpp-no-deduction-guides
-
+// Clang 5 will generate bad implicit deduction guides
+//  Specifically, for the copy constructor.
 
 // template<class Container>
 //   queue(Container) -> queue<typename Container::value_type, Container>;
diff --git a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
index 4ae11376b2b0..675f95fcbc0a 100644
--- a/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp
@@ -9,7 +9,10 @@
 
 // <stack>
 // UNSUPPORTED: c++98, c++03, c++11, c++14
+// UNSUPPORTED: clang-5
 // UNSUPPORTED: libcpp-no-deduction-guides
+// Clang 5 will generate bad implicit deduction guides
+//	Specifically, for the copy constructor.
 
 
 // template<class Container>