diff --git a/ldap_locks.py b/ldap_locks.py
index 469fda9..c23c201 100644
--- a/ldap_locks.py
+++ b/ldap_locks.py
@@ -135,6 +135,7 @@ class LdapLockHolder:
         tomber.
         """
         try:
+            value = str(value)
             host, pid, begin = self.getlock(item, value)
             time_left = self.timeout - (time.time() - begin)
             if time_left <= 0:
@@ -183,8 +184,9 @@ class LdapLockHolder:
         """
         Libère le lock "$item=$value,$LOCKS_DN".
         """
+        value = str(value)
         try:
-            if force or str(value) in self.locks[Id][item]:
+            if force or value in self.locks[Id][item]:
                 self.conn.delete_s("%s=%s,%s" % (item, value, LOCKS_DN))
         except ldap.NO_SUCH_OBJECT:
             pass
@@ -201,7 +203,7 @@ class LdapLockHolder:
         Trouve le lock item=value, et renvoie le contenu de lockinfo
         via un triplet host, pid, begin
         """
-
+        value = str(value)
         try:
             result = self.conn.search_s('%s=%s,%s' % (item, value, LOCKS_DN), 0)
             host, pid, begin = result[0][1]['lockid'][0].split('-')