diff --git a/.travis.yml b/.travis.yml
index 387e6772c..814325dbe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -86,12 +86,12 @@ before_script:
  - source bootstrap.sh
  - |
    if [[ $(uname -s) == 'Linux' ]]; then
-     mason install clang++ 3.9.0
-     export PATH=$(mason prefix clang++ 3.9.0)/bin:${PATH}
-     mason install llvm-cov 3.9.0
-     export PATH=$(mason prefix llvm-cov 3.9.0)/bin:${PATH}
+     mason install clang++ 3.9.1
+     export PATH=$(mason prefix clang++ 3.9.1)/bin:${PATH}
+     mason install llvm-cov 3.9.1
+     export PATH=$(mason prefix llvm-cov 3.9.1)/bin:${PATH}
      which llvm-cov
-     export LLVM_COV="$(mason prefix llvm-cov 3.9.0)/bin/llvm-cov"
+     export LLVM_COV="$(mason prefix llvm-cov 3.9.1)/bin/llvm-cov"
    fi
  - ccache --version
  - ccache -p || true
diff --git a/bootstrap.sh b/bootstrap.sh
index f7d0ce334..32e1db0fc 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -11,7 +11,7 @@ todo
 - shrink icu data
 '
 
-MASON_VERSION="3e2944322"
+MASON_VERSION="v0.5.0"
 
 function setup_mason() {
     if [[ ! -d ./.mason ]]; then