diff --git a/phpquery b/phpquery
index 16b33cd..3e18be6 100755
--- a/phpquery
+++ b/phpquery
@@ -181,14 +181,14 @@ action() {
     case "$action" in
 	check_mod)
 	    [ -z "$version" -o -z "$sapi" ] && usage "You need to specify version (-v) and sapi (-s)"
-	    check_version $version || usage "Invalid PHP version ($version) specified"
-	    check_sapi $version $sapi || usage "Invalid SAPI ($sapi) specified"
-	    check_mod $version $sapi $mod || ret=$?
+	    check_version "$version" || usage "Invalid PHP version ($version) specified"
+	    check_sapi "$version" "$sapi" || usage "Invalid SAPI ($sapi) specified"
+	    check_mod "$version" "$sapi" "$mod" || ret=$?
 	    ;;
 	check_sapi)
 	    [ -z "$version" ] && usage "You need to specify version (-v)"
-	    check_version $version || usage "Invalid PHP version ($version) specified"
-	    check_sapi $version $sapi || ret=$?
+	    check_version "$version" || usage "Invalid PHP version ($version) specified"
+	    check_sapi "$version" "$sapi" || ret=$?
 	    if [ "$ret" -eq 0 ]; then
 		output "$sapi"
 	    fi
@@ -200,8 +200,8 @@ action() {
 	    fi
 	    ;;
 	list_version) list_version || ret=$?;;
-	list_mod) list_mod $version $sapi $verbose || ret=$?;;
-	list_sapi) list_sapi $version || ret=$?;;
+	list_mod) list_mod "$version" "$sapi" "$verbose" || ret=$?;;
+	list_sapi) list_sapi "$version" || ret=$?;;
 	*) usage "Unknown action $action";;
     esac
 }