diff --git a/setup.sh b/setup.sh
index 925d87e83..0d990d9da 100755
--- a/setup.sh
+++ b/setup.sh
@@ -7,7 +7,7 @@
 echo "Executing Wally setup.sh"
 
 # Path to Wally repository
-WALLY=$(dirname ${BASH_SOURCE})
+WALLY=$(dirname ${BASH_SOURCE[0]:-$0})
 export WALLY=$(cd "$WALLY" && pwd)
 echo \$WALLY set to ${WALLY}