--- a/.travis.yml	Thu Mar 10 21:35:23 2016 +0800
+++ b/.travis.yml	Thu Mar 10 21:37:35 2016 +0800
@@ -1,23 +1,55 @@
 language: c
+
+os:
+  - linux
+  - osx
+
+env:
+  matrix:
+    - BUNDLEDLIBTOM=--disable-bundled-libtom WEXTRAFLAGS=-Werror
+    - BUNDLEDLIBTOM=--enable-bundled-libtom
+    - MULTI=1
+    - NOWRITEV=1
+
+# TODO: remove this section when libtomcrypt compiles on OSX: https://github.com/libtom/libtomcrypt/issues/82
+matrix:
+  exclude:
+    - os: osx
+      env: BUNDLEDLIBTOM=--disable-bundled-libtom WEXTRAFLAGS=-Werror
+    - os: osx
+      env: MULTI=1
+    - os: osx
+      env: NOWRITEV=1
+
 compiler:
   - gcc
+  - clang
 
-script: 
-  - autoconf && autoheader && ./configure $BUNDLEDLIBTOM CFLAGS="-O2 -Wall -Wno-pointer-sign $WEXTRAFLAGS" --prefix=$HOME/inst 
-  - test "$NOWRITEV" && sed -i s/HAVE_WRITEV/DONT_HAVE_WRITEV/ config.h || true
-  - make install
+# container-based builds
+sudo: false
+addons:
+  apt:
+    packages:
+    # packages list: https://github.com/travis-ci/apt-package-whitelist/blob/master/ubuntu-precise
+    - zlib1g-dev
+    - libtomcrypt-dev
+    - libtommath-dev
+
+
+before_install:
+  - if [ "$CC" = "clang" ]; then WEXTRAFLAGS="$WEXTRAFLAGS -Wno-error=incompatible-library-redeclaration" ; fi  # workaround
+
+install:
+  - if [ "$TRAVIS_OS_NAME" = "osx" -a "$BUNDLEDLIBTOM" != "--enable-bundled-libtom" ]; then brew update > /dev/null && brew install libtomcrypt libtommath ; fi
+
+script:
+  - autoconf && autoheader && ./configure "$BUNDLEDLIBTOM" CFLAGS="-O2 -Wall -Wno-pointer-sign $WEXTRAFLAGS" --prefix="$HOME/inst"
+  - if [ "$NOWRITEV" = "1" ]; then sed -i s/HAVE_WRITEV/DONT_HAVE_WRITEV/ config.h ; fi
+  - make -j3 install
+
+after_success:
   - ~/inst/bin/dropbearkey -t rsa -f testrsa
   - ~/inst/bin/dropbearkey -t dss -f testdss
   - ~/inst/bin/dropbearkey -t ecdsa -f testec256 -s 256
   - ~/inst/bin/dropbearkey -t ecdsa -f testec384 -s 384
   - ~/inst/bin/dropbearkey -t ecdsa -f testec521 -s 521
-
-before_install:
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq libz-dev libtomcrypt-dev libtommath-dev
-
-env: 
-  - BUNDLEDLIBTOM=--disable-bundled-libtom WEXTRAFLAGS=-Werror
-  - BUNDLEDLIBTOM=--enable-bundled-libtom
-  - MULTI=1
-  - NOWRITEV=1