diff --git a/.travis.yml b/.travis.yml
index 33e65c4ba..27978e4a4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,4 @@
-# Build matrix / environment variable are explained on:
+# Build matrix / environment variables are explained on:
 # http://about.travis-ci.org/docs/user/build-configuration/
 # This file can be validated on:
 # http://lint.travis-ci.org/
@@ -6,54 +6,37 @@
 # http://stackoverflow.com/questions/22111549/travis-ci-with-clang-3-4-and-c11/30925448#30925448
 # to allow C++11, though we are not yet building with -std=c++11
 
-#before_install: pyenv install 3.5.4 && pyenv global 3.5.4
-before_install: pyenv global 3.6
-# https://docs.travis-ci.com/user/languages/python/
-# "for Trusty, this means 2.7.6 and 3.4.3"
+before_install:
+- source travis.before_install.${TRAVIS_OS_NAME}.sh
 install:
-- if [[ $TRAVIS_OS_NAME == osx ]]; then
-     brew update;
-     brew install python3 ninja;
-     python3 -m venv venv;
-     source venv/bin/activate;
-  elif [[ $TRAVIS_OS_NAME == linux ]]; then
-     wget https://github.com/ninja-build/ninja/releases/download/v1.7.2/ninja-linux.zip;
-     unzip -q ninja-linux.zip -d build;
-  fi
-- pip3 install meson
-# /usr/bin/gcc is 4.6 always, but gcc-X.Y is available.
-- if [[ $CXX = g++ ]]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
-# /usr/bin/clang has a conflict with gcc, so use clang-X.Y.
-- if [[ $CXX = clang++ ]]; then export CXX="clang++-3.5" CC="clang-3.5"; fi
-- echo ${PATH}
-- ls /usr/local
-- ls /usr/local/bin
-- export PATH="${PWD}"/build:/usr/local/bin:/usr/bin:${PATH}
-- echo ${CXX}
-- ${CXX} --version
-- which valgrind
+- source travis.install.${TRAVIS_OS_NAME}.sh
 addons:
   apt:
     sources:
-    - ubuntu-toolchain-r-test
+    #- ubuntu-toolchain-r-test
     - llvm-toolchain-precise-3.5
     packages:
-    - gcc-4.9
-    - g++-4.9
+    #- gcc-4.9
+    #- g++-4.9
     - clang-3.5
     - valgrind
-os:
-  - linux
 language: cpp
-compiler:
-  - gcc
-  - clang
 script: ./travis.sh
-env:
-  matrix:
-    - LIB_TYPE=static BUILD_TYPE=release
-    - LIB_TYPE=shared BUILD_TYPE=debug
+matrix:
+  allow_failures:
+    - os: osx
+matrix:
+  include:
+    - os: osx
+      osx_image: xcode9.4
+      compiler: clang
+      #env: PYENV_ROOT=/usr/local/var/pyenv
+      env: LIB_TYPE=static BUILD_TYPE=release
+      #- LIB_TYPE=shared BUILD_TYPE=debug
+    - os: linux
+      dist: trusty
+      compiler: clang
+      env: LIB_TYPE=static BUILD_TYPE=release
 notifications:
   email: false
-dist: trusty
 sudo: false
diff --git a/travis.before_install.linux.sh b/travis.before_install.linux.sh
new file mode 100644
index 000000000..18e019d84
--- /dev/null
+++ b/travis.before_install.linux.sh
@@ -0,0 +1,7 @@
+set -vex
+#before_install: pyenv install 3.5.4 && pyenv global 3.5.4
+#before_install: pyenv global 3.6
+# https://docs.travis-ci.com/user/languages/python/
+# "for Trusty, this means 2.7.6 and 3.4.3"
+
+pyenv global 3.6
diff --git a/travis.before_install.osx.sh b/travis.before_install.osx.sh
new file mode 100644
index 000000000..a8377faef
--- /dev/null
+++ b/travis.before_install.osx.sh
@@ -0,0 +1,3 @@
+set -vex
+#brew install pyenv
+#which pyenv
diff --git a/travis.install.linux.sh b/travis.install.linux.sh
new file mode 100644
index 000000000..a049f760c
--- /dev/null
+++ b/travis.install.linux.sh
@@ -0,0 +1,14 @@
+set -vex
+
+wget https://github.com/ninja-build/ninja/releases/download/v1.7.2/ninja-linux.zip
+unzip -q ninja-linux.zip -d build
+
+pip3 install meson
+# /usr/bin/gcc is 4.6 always, but gcc-X.Y is available.
+if [[ $CXX = g++ ]]; then export CXX="g++-4.9" CC="gcc-4.9"; fi
+# /usr/bin/clang has a conflict with gcc, so use clang-X.Y.
+if [[ $CXX = clang++ ]]; then export CXX="clang++-3.5" CC="clang-3.5"; fi
+echo ${PATH}
+ls /usr/local
+ls /usr/local/bin
+export PATH="${PWD}"/build:/usr/local/bin:/usr/bin:${PATH}
diff --git a/travis.install.osx.sh b/travis.install.osx.sh
new file mode 100644
index 000000000..e82bdc660
--- /dev/null
+++ b/travis.install.osx.sh
@@ -0,0 +1,12 @@
+set -vex
+
+#brew update
+brew upgrade python3
+python3 -m venv venv
+source venv/bin/activate
+
+brew install ninja
+brew install meson
+
+#brew install pyenv
+#which pyenv
diff --git a/travis.sh b/travis.sh
index 226c64d94..f0628fc56 100755
--- a/travis.sh
+++ b/travis.sh
@@ -17,6 +17,9 @@ set -vex
 
 env | sort
 
+echo ${CXX}
+${CXX} --version
+python3 --version
 meson --version
 ninja --version
 meson --buildtype ${BUILD_TYPE} --default-library ${LIB_TYPE} . build-${LIB_TYPE}