diff --git a/crm_phone/__manifest__.py b/crm_phone/__manifest__.py
index a0e9bdc..65a6053 100644
--- a/crm_phone/__manifest__.py
+++ b/crm_phone/__manifest__.py
@@ -24,6 +24,7 @@ for any help or question about this module.
     'author': "Akretion,Odoo Community Association (OCA)",
     'website': 'http://www.akretion.com/',
     'depends': ['base_phone', 'crm'],
+    'external_dependencies': {'python': ['phonenumbers']},
     'conflicts': ['crm_voip'],
     'data': [
         'security/phonecall_security.xml',
diff --git a/crm_phone/wizard/create_crm_phonecall.py b/crm_phone/wizard/create_crm_phonecall.py
index 98569da..7b6e912 100644
--- a/crm_phone/wizard/create_crm_phonecall.py
+++ b/crm_phone/wizard/create_crm_phonecall.py
@@ -3,7 +3,13 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
 from odoo import models, api, _
-import phonenumbers
+import logging
+logger = logging.getLogger(__name__)
+
+try:
+    import phonenumbers
+except ImportError:
+    logger.debug('Cannot import phonenumbers lib.')
 
 
 class WizardCreateCrmPhonecall(models.TransientModel):