diff --git a/.travis.yml b/.travis.yml
index a18de6a..e18acef 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -50,6 +50,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - *default_packages
             - g++-multilib
@@ -61,6 +62,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - clang-3.7
     - env: CONF=debug   ARCH=x86    CXX11=OFF CCACHE_CPP2=yes
@@ -69,6 +71,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - *default_packages
             - g++-multilib
@@ -80,6 +83,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - clang-3.7
     - env: CONF=release ARCH=x86    CXX11=ON CCACHE_CPP2=yes
@@ -88,6 +92,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - *default_packages
             - g++-multilib
@@ -99,6 +104,7 @@ matrix:
         apt:
           sources:
             - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
           packages:
             - clang-3.7
     # coverage report