diff --git a/dfir_iris_client/case.py b/dfir_iris_client/case.py
index 1cb2d66..dfe8e77 100644
--- a/dfir_iris_client/case.py
+++ b/dfir_iris_client/case.py
@@ -84,7 +84,7 @@ def get_case(self, cid: int) -> ApiResponse:
 
     def add_case(self, case_name: str, case_description: str, case_customer: Union[str, int],
                  case_classification: Union[str, int], soc_id: str, custom_attributes: dict = None,
-                 create_customer=False) -> ApiResponse:
+                 create_customer=False, severity_id=4) -> ApiResponse:
         """Creates a new case. If create_customer is set to true and the customer doesn't exist,
         it is created. Otherwise an error is returned.
         
@@ -100,6 +100,7 @@ def add_case(self, case_name: str, case_description: str, case_customer: Union[s
           soc_id: SOC Number
           custom_attributes: Custom attributes of the case
           create_customer: Set to true to create the customer is doesn't exists. (Default value = False)
+          severity_id: The case severity. (Default value = 4 [Low severity])
 
         Returns:
           ApiResponse object
@@ -147,6 +148,7 @@ def add_case(self, case_name: str, case_description: str, case_customer: Union[s
             "classification_id": case_classification,
             "case_soc_id": soc_id,
             "case_description": case_description,
+            "severity_id": severity_id,
             "custom_attributes": custom_attributes
         }
         resp = self._s.pi_post('manage/cases/add', data=body)