diff --git a/.travis.yml b/.travis.yml
index 043232c..57b44e9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -223,7 +223,7 @@ matrix:
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=11,14,1z
 
     - os: linux
-      compiler: clang
+      compiler: clang++
       env: CMAKE=1
       install: true
       script:
@@ -231,6 +231,16 @@ matrix:
       - cmake ..
       - cmake --build . --target check
 
+    - os: linux
+      compiler: clang++
+      env: CMAKE_SUBDIR_TEST=1
+      install: true
+      script:
+      - cd test/cmake_subir_test && mkdir __build__ && cd __build__
+      - cmake ..
+      - cmake --build .
+      - cmake --build . --target check
+
 install:
   - BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
   - cd ..
diff --git a/test/cmake_subdir_test/CMakeLists.txt b/test/cmake_subdir_test/CMakeLists.txt
new file mode 100644
index 0000000..a2007ea
--- /dev/null
+++ b/test/cmake_subdir_test/CMakeLists.txt
@@ -0,0 +1,17 @@
+# Copyright 2018 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+cmake_minimum_required(VERSION 3.5)
+
+project(cmake_subdir_test LANGUAGES CXX)
+
+add_subdirectory(../.. boostorg/mp11)
+
+add_executable(main main.cpp)
+target_link_libraries(main Boost::mp11)
+
+enable_testing()
+add_test(NAME main COMMAND main)
+
+add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
diff --git a/test/cmake_subdir_test/main.cpp b/test/cmake_subdir_test/main.cpp
new file mode 100644
index 0000000..da23712
--- /dev/null
+++ b/test/cmake_subdir_test/main.cpp
@@ -0,0 +1,8 @@
+#include <boost/mp11.hpp>
+using namespace boost::mp11;
+
+int main()
+{
+    using L1 = mp_list<int, float, int, float>;
+    return mp_size<mp_unique<L1>>::value == 2? 0: 1;
+}