diff --git a/common.sh b/common.sh
index 9d753fd95ae4d9152aad93f7da57b00a9def0093..292f5a37fecafdd96172beaa73a6d1f4088bea06 100644
--- a/common.sh
+++ b/common.sh
@@ -47,7 +47,7 @@ checkUser()
 # Check whether the output file will be in a existent and writable directory
 checkOutput()
 {
-    local dir="$(dirname $1)"
+    local dir="$(dirname "$1")"
     test -d "$dir" -a -w "$dir"
     return $?
 }