diff --git a/llm_server/llm/hf_textgen/generate.py b/llm_server/llm/hf_textgen/generate.py
index c0fa4f3..ec70d54 100644
--- a/llm_server/llm/hf_textgen/generate.py
+++ b/llm_server/llm/hf_textgen/generate.py
@@ -14,7 +14,8 @@ def prepare_json(json_data: dict):
         seed = None
     typical_p = json_data.get('typical_p', None)
     if typical_p >= 1:
-        typical_p = 0.999
+        # https://github.com/huggingface/text-generation-inference/issues/929
+        typical_p = 0.998
     return {
         'inputs': json_data.get('prompt', ''),
         'parameters': {
diff --git a/llm_server/routes/request_handler.py b/llm_server/routes/request_handler.py
index a88bdd9..de55711 100644
--- a/llm_server/routes/request_handler.py
+++ b/llm_server/routes/request_handler.py
@@ -45,7 +45,7 @@ class OobaRequestHandler:
     def get_parameters(self):
         request_valid_json, self.request_json_body = validate_json(self.request.data)
         if not request_valid_json:
-            raise InvalidJSONError
+            return jsonify({'code': 400, 'msg': 'Invalid JSON'}), 400
         parameters = self.request_json_body.copy()
         del parameters['prompt']
         return parameters
diff --git a/llm_server/routes/v1/generate.py b/llm_server/routes/v1/generate.py
index cf04c1e..668856a 100644
--- a/llm_server/routes/v1/generate.py
+++ b/llm_server/routes/v1/generate.py
@@ -1,15 +1,15 @@
 from flask import jsonify, request
-from requests.exceptions import InvalidJSONError
 
 from . import bp
+from ..helpers.http import validate_json
 from ..request_handler import OobaRequestHandler
 
 
 @bp.route('/generate', methods=['POST'])
 def generate():
-    try:
+    request_valid_json, request_json_body = validate_json(request.data)
+    if not request_valid_json or not request_json_body.get('prompt') or not request_json_body.get('parameters'):
+        return jsonify({'code': 400, 'msg': 'Invalid JSON'}), 400
+    else:
         handler = OobaRequestHandler(request)
         return handler.handle_request()
-    except InvalidJSONError:
-        # The request handler will throw an error if the client sent invalid JSON
-        return jsonify({'code': 400, 'msg': 'Invalid JSON'}), 400