diff --git a/bin/git-contrib b/bin/git-contrib
index 15b7500..4e6271a 100755
--- a/bin/git-contrib
+++ b/bin/git-contrib
@@ -1,10 +1,10 @@
 #!/bin/sh
 
-user=$1
+user="$1"
 if test -z "$user"; then
   echo "user name required." && exit 1
 else
   count=`git log --oneline --pretty="format: %an" | grep "$user" | wc -l`
   test $count -eq 0 && echo "$user did not contribute." && exit 1
-  git shortlog | grep $user -A $count
+  git shortlog | grep "$user" -A $count
 fi
\ No newline at end of file