diff --git a/.travis.yml b/.travis.yml
index e245b1a..61a1909 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,9 @@
+os:
+    - linux
+    - osx
+
 language: python
 python:
     - '3.5'
+
 script: ./t/regress.sh
diff --git a/t/regress.sh b/t/regress.sh
index a7bdd64..41af06e 100755
--- a/t/regress.sh
+++ b/t/regress.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+. $(dirname $0)/regress_util.sh
+
 ## List of tests to ignore
 test_ignore_list=( test_fail )
 ignore_test () {
@@ -11,9 +13,6 @@ ignore_test () {
         fi
 }
 
-test_root=$(dirname $(readlink -f $0))
-wit_root=$(readlink -f $test_root/..)
-
 export PATH=$wit_root:${PATH}
 
 timestamp=`date +'%Y-%m-%dT%H-%M-%S'`
diff --git a/t/regress_util.sh b/t/regress_util.sh
index d919a04..3108509 100755
--- a/t/regress_util.sh
+++ b/t/regress_util.sh
@@ -1,8 +1,8 @@
 #!/bin/sh
 
+test_root=$(dirname $(perl -MCwd -M5.14.0 -e "say Cwd::realpath('$0')"))
+wit_root=$(perl -MCwd -M5.14.0 -e "say Cwd::realpath('$test_root/..')")
 wit_repo='git@github.com:sifive/wit'
-test_root=$(dirname $(readlink -f $0))
-wit_root=$(readlink -f $test_root/..)
 
 export PATH=$wit_root:${PATH}