diff --git a/cromulant/args.py b/cromulant/args.py
index 5115db5..58fb192 100644
--- a/cromulant/args.py
+++ b/cromulant/args.py
@@ -18,6 +18,7 @@ class Args:
     width: int = 0
     height: int = 0
     program: str = ""
+    speed: str = ""
 
     @staticmethod
     def prepare() -> None:
@@ -42,6 +43,7 @@ class Args:
             "width",
             "height",
             "program",
+            "speed",
         ]
 
         for n_item in normals:
diff --git a/cromulant/argspec.py b/cromulant/argspec.py
index d99a780..bc07351 100644
--- a/cromulant/argspec.py
+++ b/cromulant/argspec.py
@@ -123,3 +123,10 @@ class ArgSpec:
             type=str,
             info="The internal name of the program",
         )
+
+        ArgSpec.add_argument(
+            "speed",
+            type=str,
+            choices=["fast", "normal", "slow"],
+            info="Use this update speed",
+        )
diff --git a/cromulant/settings.py b/cromulant/settings.py
index 1e22bfb..922e096 100644
--- a/cromulant/settings.py
+++ b/cromulant/settings.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from .args import Args
 from .window import Window
 from .storage import Storage
 
@@ -17,8 +18,14 @@ class Settings:
     @staticmethod
     def prepare() -> None:
         settings = Storage.get_settings()
+        changed = False
+
+        if Args.speed:
+            Settings.speed = Args.speed
+            changed = True
+        else:
+            Settings.speed = settings.get("speed", "normal")
 
-        Settings.speed = settings.get("speed", "normal")
         speed = Settings.speed.capitalize()
         Window.speed.setCurrentText(speed)
 
@@ -29,6 +36,9 @@ class Settings:
 
         Settings.merge = settings.get("merge", True)
 
+        if changed:
+            Settings.save()
+
     @staticmethod
     def save() -> None:
         settings = {