diff --git a/lib/ulib/.ulibver b/lib/ulib/.ulibver
index c605ea6..9c1e68d 100644
--- a/lib/ulib/.ulibver
+++ b/lib/ulib/.ulibver
@@ -1 +1 @@
-001003000
+001004000
diff --git a/lib/ulib/compat b/lib/ulib/compat
index f7251ab..5d2d87e 100644
--- a/lib/ulib/compat
+++ b/lib/ulib/compat
@@ -20,17 +20,26 @@ if check_sysinfos -s macosx; then
     function tolower() { tr A-Z a-z <<<"$*"; }
     function toupper() { tr a-z A-Z <<<"$*"; }
     function is_yes() {
+        case "$1" in
+        o|oui|y|yes|v|vrai|t|true|on) return 0;;
+        O|OUI|Y|YES|V|VRAI|T|TRUE|ON) return 0;;
+        esac
+        isnum "$1" && [ "$1" -ne 0 ] && return 0
+        # pour les perfs, n'utiliser tolower que ici
         case "$(tolower "$1")" in
         o|oui|y|yes|v|vrai|t|true|on) return 0;;
         esac
-        isnum "$1" && [ "$1" -ne 0 ] && return 0
         return 1
     }
     function is_no() {
+        case "$1" in
+        n|non|no|f|faux|false|off) return 0;;
+        N|NON|NO|F|FAUX|FALSE|OFF) return 0;;
+        esac
+        isnum "$1" && [ "$1" -eq 0 ] && return 0
         case "$(tolower "$1")" in
         n|non|no|f|faux|false|off) return 0;;
         esac
-        isnum "$1" && [ "$1" -eq 0 ] && return 0
         return 1
     }