clang 3.7 -> 3.9
diff --git a/ci/install-linux.sh b/ci/install-linux.sh
index 02a1943..05e2cb2 100755
--- a/ci/install-linux.sh
+++ b/ci/install-linux.sh
@@ -41,7 +41,7 @@
     echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | \
         sudo tee /etc/apt/sources.list.d/bazel.list
     curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add -
-    sudo apt-get update && sudo apt-get install -y bazel gcc-4.9 g++-4.9 clang-3.7
+    sudo apt-get update && sudo apt-get install -y bazel gcc-4.9 g++-4.9 clang-3.9
 elif [ "${CXX}" = "clang++" ]; then
     # Use ccache, assuming $HOME/bin is in the path, which is true in the Travis build environment.
     ln -sf /usr/bin/ccache $HOME/bin/${CXX};