diff --git a/.travis.yml b/.travis.yml
index 34b697d..272bf03 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -92,6 +92,12 @@ matrix:
     - os: linux
       compiler: clang++
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - libstdc++-5-dev
+          sources:
+            - ubuntu-toolchain-r-test
 
     - os: linux
       compiler: clang++-libc++