diff --git a/lib/datadog_api_client/v1/model_base.rb b/lib/datadog_api_client/v1/model_base.rb
index 203568f08509..d56c5b331d47 100644
--- a/lib/datadog_api_client/v1/model_base.rb
+++ b/lib/datadog_api_client/v1/model_base.rb
@@ -83,6 +83,11 @@ def build_from_hash(attributes)
       end
 
       if self.respond_to?(:additional_properties)
+        self.class.openapi_types.each_key do |key|
+          json_key = self.class.attribute_map[key]
+          next unless json_key && attributes.key?(json_key)
+          self.additional_properties[json_key] = self.send(key)
+        end
         attributes.each_with_object({}) { |(k, v), h|
           if (!self.class.attribute_map.key?(k.to_sym))
             self.additional_properties[k.to_sym] = v
diff --git a/lib/datadog_api_client/v2/model_base.rb b/lib/datadog_api_client/v2/model_base.rb
index 7bdfde0c6bcd..357c5187628e 100644
--- a/lib/datadog_api_client/v2/model_base.rb
+++ b/lib/datadog_api_client/v2/model_base.rb
@@ -83,6 +83,11 @@ def build_from_hash(attributes)
       end
 
       if self.respond_to?(:additional_properties)
+        self.class.openapi_types.each_key do |key|
+          json_key = self.class.attribute_map[key]
+          next unless json_key && attributes.key?(json_key)
+          self.additional_properties[json_key] = self.send(key)
+        end
         attributes.each_with_object({}) { |(k, v), h|
           if (!self.class.attribute_map.key?(k.to_sym))
             self.additional_properties[k.to_sym] = v