diff --git a/.generator/src/generator/templates/model_generic.j2 b/.generator/src/generator/templates/model_generic.j2
index 8ebe035e1b7e..256a4c749ea3 100644
--- a/.generator/src/generator/templates/model_generic.j2
+++ b/.generator/src/generator/templates/model_generic.j2
@@ -108,6 +108,21 @@
 {%- endif %}
     end
 
+{%- if model.get("x-keep-typed-in-additional-properties") %}
+
+    # Builds the object from hash, also mirroring typed fields into additional_properties.
+    # @param attributes [Hash] Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    # @!visibility private
+    def build_from_hash(attributes)
+      super
+      self.class.attribute_map.each_pair do |attr, json_key|
+        self.additional_properties[json_key] = self.send(attr) if attributes.key?(json_key)
+      end
+      self
+    end
+{%- endif %}
+
 {%- set ns = namespace(hasValidation=False) %}
 {%- for attr, definition in model.get("properties", {}).items() %}
       {%- set required = attr in model.get("required", []) %}
diff --git a/lib/datadog_api_client/v1/models/usage_summary_date.rb b/lib/datadog_api_client/v1/models/usage_summary_date.rb
index ceccbdc71fa8..1a1b006e6103 100644
--- a/lib/datadog_api_client/v1/models/usage_summary_date.rb
+++ b/lib/datadog_api_client/v1/models/usage_summary_date.rb
@@ -3110,6 +3110,18 @@ def initialize(attributes = {})
       self.additional_properties[:'workflow_executions_usage_sum'] = self.workflow_executions_usage_sum if attributes.key?(:'workflow_executions_usage_sum')
     end
 
+    # Builds the object from hash, also mirroring typed fields into additional_properties.
+    # @param attributes [Hash] Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    # @!visibility private
+    def build_from_hash(attributes)
+      super
+      self.class.attribute_map.each_pair do |attr, json_key|
+        self.additional_properties[json_key] = self.send(attr) if attributes.key?(json_key)
+      end
+      self
+    end
+
     # Returns the object in the form of hash, with additionalProperties support.
     # @return [Hash] Returns the object in the form of hash
     # @!visibility private
diff --git a/lib/datadog_api_client/v1/models/usage_summary_date_org.rb b/lib/datadog_api_client/v1/models/usage_summary_date_org.rb
index 5f94c9ef8123..d614768c93d2 100644
--- a/lib/datadog_api_client/v1/models/usage_summary_date_org.rb
+++ b/lib/datadog_api_client/v1/models/usage_summary_date_org.rb
@@ -3168,6 +3168,18 @@ def initialize(attributes = {})
       self.additional_properties[:'workflow_executions_usage_sum'] = self.workflow_executions_usage_sum if attributes.key?(:'workflow_executions_usage_sum')
     end
 
+    # Builds the object from hash, also mirroring typed fields into additional_properties.
+    # @param attributes [Hash] Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    # @!visibility private
+    def build_from_hash(attributes)
+      super
+      self.class.attribute_map.each_pair do |attr, json_key|
+        self.additional_properties[json_key] = self.send(attr) if attributes.key?(json_key)
+      end
+      self
+    end
+
     # Returns the object in the form of hash, with additionalProperties support.
     # @return [Hash] Returns the object in the form of hash
     # @!visibility private
diff --git a/lib/datadog_api_client/v1/models/usage_summary_response.rb b/lib/datadog_api_client/v1/models/usage_summary_response.rb
index 9db199de7b58..2699bbd38c86 100644
--- a/lib/datadog_api_client/v1/models/usage_summary_response.rb
+++ b/lib/datadog_api_client/v1/models/usage_summary_response.rb
@@ -3221,6 +3221,18 @@ def initialize(attributes = {})
       self.additional_properties[:'workflow_executions_usage_agg_sum'] = self.workflow_executions_usage_agg_sum if attributes.key?(:'workflow_executions_usage_agg_sum')
     end
 
+    # Builds the object from hash, also mirroring typed fields into additional_properties.
+    # @param attributes [Hash] Model attributes in the form of hash
+    # @return [Object] Returns the model itself
+    # @!visibility private
+    def build_from_hash(attributes)
+      super
+      self.class.attribute_map.each_pair do |attr, json_key|
+        self.additional_properties[json_key] = self.send(attr) if attributes.key?(json_key)
+      end
+      self
+    end
+
     # Returns the object in the form of hash, with additionalProperties support.
     # @return [Hash] Returns the object in the form of hash
     # @!visibility private
diff --git a/spec/v1/deserialization_spec.rb b/spec/v1/deserialization_spec.rb
index d27493e9f81a..d3f7abeb5200 100644
--- a/spec/v1/deserialization_spec.rb
+++ b/spec/v1/deserialization_spec.rb
@@ -94,4 +94,27 @@
     expect(data.data.attributes.destination.data[:type]).to eq "A non existent destination"
     end
   end
+
+  describe 'build_from_hash typed fields in additional_properties' do
+    it 'should mirror typed fields into additional_properties when x-keep-typed-in-additional-properties is set' do
+      data = DatadogAPIClient::V1::UsageSummaryResponse.build_from_hash({
+        agent_host_top99p_sum: 42,
+        apm_host_top99p_sum: 99
+      })
+
+      expect(data).to be_a DatadogAPIClient::V1::UsageSummaryResponse
+      expect(data.agent_host_top99p_sum).to eq 42
+      expect(data.additional_properties[:'agent_host_top99p_sum']).to eq 42
+      expect(data.additional_properties[:'apm_host_top99p_sum']).to eq 99
+    end
+
+    it 'should not include typed fields absent from the JSON in additional_properties' do
+      data = DatadogAPIClient::V1::UsageSummaryResponse.build_from_hash({
+        agent_host_top99p_sum: 7
+      })
+
+      expect(data.additional_properties[:'agent_host_top99p_sum']).to eq 7
+      expect(data.additional_properties.key?(:'apm_host_top99p_sum')).to be false
+    end
+  end
 end