diff --git a/.travis.yml b/.travis.yml
index 2a737749..aee42cd3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,11 +30,19 @@ matrix:
 
   - os: linux
     compiler: clang
-    env: COMPILER=clang++-4.0
+    env: COMPILER=clang++-3.4
     addons:
       apt:
-        sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-trusty-4.0']
-        packages: ['g++-6', 'clang-4.0']
+        sources: ['ubuntu-toolchain-r-test']
+        packages: ['g++-6', 'clang-3.4']
+
+  - os: linux
+    compiler: clang
+    env: COMPILER=clang++-3.5
+    addons:
+      apt:
+        sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.5']
+        packages: ['g++-6', 'clang-3.5']
 
 ################
 # build script #