diff --git a/doc/scripts/pkgconfig.sh b/doc/scripts/pkgconfig.sh
index e25756c..895f3b7 100755
--- a/doc/scripts/pkgconfig.sh
+++ b/doc/scripts/pkgconfig.sh
@@ -67,7 +67,7 @@ while getopts iuP: name; do
 			uninstall=1
 			;;
 		P)
-			PREFIX="$2"
+			PREFIX="$OPTARG"
 			;;
 		?)
 			_usage