diff --git a/monkey/common/agent_configuration/agent_sub_configuration_schemas.py b/monkey/common/agent_configuration/agent_sub_configuration_schemas.py
index 15fdd6ba9..e666407ac 100644
--- a/monkey/common/agent_configuration/agent_sub_configuration_schemas.py
+++ b/monkey/common/agent_configuration/agent_sub_configuration_schemas.py
@@ -135,7 +135,7 @@ class ExploitationConfigurationSchema(Schema):
 
 
 class PropagationConfigurationSchema(Schema):
-    maximum_depth = fields.Int()
+    maximum_depth = fields.Int(validate=validate.Range(min=1))
     network_scan = fields.Nested(NetworkScanConfigurationSchema)
     exploitation = fields.Nested(ExploitationConfigurationSchema)