diff --git a/README.md b/README.md
index c6c3872..0c4ceb3 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ curl http://127.0.0.1:8000/v1/chat/completions \
 
 ### Thinking effort
 
-- `--reasoning-effort` (choice of low,medium,high)<br>
+- `--reasoning-effort` (choice of minimal,low,medium,high)<br>
 GPT-5 has a configurable amount of "effort" it can put into thinking, which may cause it to take more time for a response to return, but may overall give a smarter answer. Applying this parameter after `serve` forces the server to use this reasoning effort by default, unless overrided by the API request with a different effort set. The default reasoning effort without setting this parameter is `medium`.
 
 ### Thinking summaries
diff --git a/chatmock/cli.py b/chatmock/cli.py
index 3868896..3e28e29 100644
--- a/chatmock/cli.py
+++ b/chatmock/cli.py
@@ -85,7 +85,7 @@ def main() -> None:
     )
     p_serve.add_argument(
         "--reasoning-effort",
-        choices=["low", "medium", "high", "none"],
+        choices=["minimal", "low", "medium", "high"],
         default=os.getenv("CHATGPT_LOCAL_REASONING_EFFORT", "medium").lower(),
         help="Reasoning effort level for Responses API (default: medium)",
     )
diff --git a/chatmock/reasoning.py b/chatmock/reasoning.py
index b6fec10..7918ce2 100644
--- a/chatmock/reasoning.py
+++ b/chatmock/reasoning.py
@@ -9,7 +9,7 @@ def build_reasoning_param(
     effort = (base_effort or "").strip().lower()
     summary = (base_summary or "").strip().lower()
 
-    valid_efforts = {"low", "medium", "high", "none"}
+    valid_efforts = {"minimal", "low", "medium", "high"}
     valid_summaries = {"auto", "concise", "detailed", "none"}
 
     if isinstance(overrides, dict):
diff --git a/chatmock/upstream.py b/chatmock/upstream.py
index 6742eb7..c7c886e 100644
--- a/chatmock/upstream.py
+++ b/chatmock/upstream.py
@@ -58,7 +58,7 @@ def start_upstream_request(
         return None, resp
 
     include: List[str] = []
-    if isinstance(reasoning_param, dict) and reasoning_param.get("effort") != "none":
+    if isinstance(reasoning_param, dict):
         include.append("reasoning.encrypted_content")
 
     client_session_id = None
diff --git a/gui.py b/gui.py
index f444437..bb654b3 100644
--- a/gui.py
+++ b/gui.py
@@ -298,7 +298,7 @@ class MainWindow(QtWidgets.QMainWindow):
         opts.setVerticalSpacing(8)
         opts.addWidget(QtWidgets.QLabel("Reasoning Effort"), 0, 0)
         self.effort = QtWidgets.QComboBox()
-        self.effort.addItems(["low", "medium", "high", "none"])  # default medium
+        self.effort.addItems(["minimal", "low", "medium", "high"])  # default medium
         self.effort.setCurrentText("medium")
         self.effort.setSizeAdjustPolicy(QtWidgets.QComboBox.AdjustToContents)
         self.effort.setMinimumContentsLength(7)