diff --git a/Tools/CodeStyle/ardupilot-astyle.sh b/Tools/CodeStyle/ardupilot-astyle.sh
index 8c1a9a61fb..61cda6e677 100755
--- a/Tools/CodeStyle/ardupilot-astyle.sh
+++ b/Tools/CodeStyle/ardupilot-astyle.sh
@@ -1,5 +1,6 @@
 #!/bin/sh
-if [[ "$OSTYPE" == "darwin"* ]]; then
+
+if [ $(uname) = "Darwin" ]; then
     DIR=$(dirname $(greadlink -f $0))
 else
     DIR=$(dirname $(readlink -f $0))