diff --git a/.travis.yml b/.travis.yml
index ff0257a7..ae9b3df6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -199,6 +199,33 @@ matrix:
         apt:
           packages:
             - libc++-dev
+            - clang-5.0
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-5.0
+
+    - os: linux
+      compiler: clang++-6.0
+      env: TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-6.0
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-6.0
+
+    - os: linux
+      compiler: clang++-libc++
+      env: TOOLSET=clang COMPILER=clang++-libc++ CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - clang-6.0
+            - libc++-dev
+          sources:
+            - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-6.0
 
     - os: osx
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z