diff --git a/.travis.yml b/.travis.yml
index 214e2c41..d27e93f7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -85,6 +85,12 @@ matrix:
       # trusty default (clang 3.9.0)
     - os: linux
       env: TOOLSET=clang CXXSTD=03,11,14,1z
+      addons:
+        apt:
+          packages:
+            - libstdc++-4.9-dev
+          sources:
+            - ubuntu-toolchain-r-test
 
     - os: linux
       env: TOOLSET=clang-3.5 CXXSTD=03,11,14,1z
@@ -92,6 +98,7 @@ matrix:
         apt:
           packages:
             - clang-3.5
+            - libstdc++-4.9-dev
           sources:
             - ubuntu-toolchain-r-test
 
@@ -121,6 +128,7 @@ matrix:
         apt:
           packages:
             - clang-3.8
+            - libstdc++-4.9-dev
           sources:
             - ubuntu-toolchain-r-test
 
@@ -130,6 +138,7 @@ matrix:
         apt:
           packages:
             - clang-3.9
+            - libstdc++-4.9-dev
           sources:
             - ubuntu-toolchain-r-test