diff --git a/.travis.yml b/.travis.yml
index 58e0268..d749976 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -218,6 +218,28 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-precise-3.5
 
+    - os: linux
+      compiler: clang++-3.5
+      env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=c++14
+      addons:
+        apt:
+          packages:
+            - clang-3.5
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.5
+
+    - os: linux
+      compiler: clang++-3.5
+      env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=c++1z
+      addons:
+        apt:
+          packages:
+            - clang-3.5
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.5
+
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=c++03
       addons:
@@ -238,6 +260,26 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-precise-3.6
 
+    - os: linux
+      env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=c++14
+      addons:
+        apt:
+          packages:
+            - clang-3.6
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.6
+
+    - os: linux
+      env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=c++1z
+      addons:
+        apt:
+          packages:
+            - clang-3.6
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.6
+
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=c++03
       addons:
@@ -258,6 +300,26 @@ matrix:
             - ubuntu-toolchain-r-test
             - llvm-toolchain-precise-3.7
 
+    - os: linux
+      env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=c++14
+      addons:
+        apt:
+          packages:
+            - clang-3.7
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.7
+
+    - os: linux
+      env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=c++1z
+      addons:
+        apt:
+          packages:
+            - clang-3.7
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-precise-3.7
+
     - os: linux
       env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=c++03
       addons:
diff --git a/test/atomic_sp_constexpr_test.cpp b/test/atomic_sp_constexpr_test.cpp
index 2661d60..d81822d 100644
--- a/test/atomic_sp_constexpr_test.cpp
+++ b/test/atomic_sp_constexpr_test.cpp
@@ -25,6 +25,11 @@
 # undef HAVE_CONSTEXPR_INIT
 #endif
 
+#if defined( _LIBCPP_VERSION ) && ( _LIBCPP_VERSION < 5000 )
+// in libc++, atomic_flag has a non-constexpr constructor from bool
+# undef HAVE_CONSTEXPR_INIT
+#endif
+
 #if !defined( HAVE_CONSTEXPR_INIT ) || defined( BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX )
 
 int main()