diff --git a/vbox/utils/vboxplay.in b/vbox/utils/vboxplay.in
index b3a88fb1..8693b4b6 100644
--- a/vbox/utils/vboxplay.in
+++ b/vbox/utils/vboxplay.in
@@ -15,7 +15,7 @@ fi
 
 SAMPLE=$1
 VOLUME=$2
-if [ "$VOLUME" == "" ]; then
+if [ -z "$VOLUME" ]; then
    VOLUME=5;
 fi