diff --git a/tiramisu/option/ipoption.py b/tiramisu/option/ipoption.py
index 1c4278e..85ee85e 100644
--- a/tiramisu/option/ipoption.py
+++ b/tiramisu/option/ipoption.py
@@ -64,7 +64,7 @@ class IPOption(StrOption):
         try:
             new_value = str(ip_address(value))
             if value != new_value:
-                raise ValueError(f'should be {new_value}')
+                raise ValueError(_(f'should be {new_value}'))
         except ValueError:
             raise ValueError()
 
@@ -72,6 +72,8 @@ class IPOption(StrOption):
                  value: str) -> None:
         super().validate(value)
         if self.impl_get_extra('_cidr'):
+            if '/' not in value:
+                raise ValueError(_('CIDR address must have a "/"'))
             self._validate_cidr(value)
         else:
             self._validate_ip(value)