Index: binaries/data/mods/public/gui/gamesettings/attributes/GameSpeed.js
===================================================================
--- binaries/data/mods/public/gui/gamesettings/attributes/GameSpeed.js
+++ binaries/data/mods/public/gui/gamesettings/attributes/GameSpeed.js
@@ -8,7 +8,7 @@
 
 	toInitAttributes(attribs)
 	{
-		attribs.gameSpeed = this.gameSpeed;
+		attribs.gameSpeed = +this.gameSpeed;
 	}
 
 	fromInitAttributes(attribs)
@@ -27,6 +27,6 @@
 
 	setSpeed(speed)
 	{
-		this.gameSpeed = speed;
+		this.gameSpeed = +speed;
 	}
 };
Index: binaries/data/mods/public/gui/gamesetup/Pages/GameSetupPage/GameSettings/Single/Dropdowns/GameSpeed.js
===================================================================
--- binaries/data/mods/public/gui/gamesetup/Pages/GameSetupPage/GameSettings/Single/Dropdowns/GameSpeed.js
+++ binaries/data/mods/public/gui/gamesetup/Pages/GameSetupPage/GameSettings/Single/Dropdowns/GameSpeed.js
@@ -25,17 +25,22 @@
 				break;
 			}
 
-		if (this.previousAllowFastForward !== allowFastForward)
+		if (this.previousAllowFastForward === allowFastForward)
 		{
-			this.previousAllowFastForward = allowFastForward;
-			let values = prepareForDropdown(
-				g_Settings.GameSpeeds.filter(speed => !speed.FastForward || allowFastForward));
-
-			this.dropdown.list = values.Title;
-			this.dropdown.list_data = values.Speed;
+			this.setSelectedValue(g_GameSettings.gameSpeed.gameSpeed);
+			return;
 		}
+		this.previousAllowFastForward = allowFastForward;
+		let values = prepareForDropdown(
+			g_Settings.GameSpeeds.filter(speed => !speed.FastForward || allowFastForward));
+		let currentSpeed = +this.dropdown.list_data?.[this.dropdown.selected];
+		if (values.Speed.indexOf(currentSpeed) === -1)
+			this.dropdown.selected = values.Default;
 
-		this.setSelectedValue(g_GameSettings.gameSpeed.gameSpeed);
+		this.dropdown.list = values.Title;
+		this.dropdown.list_data = values.Speed;
+
+		g_GameSettings.gameSpeed.setSpeed(this.dropdown.list_data[this.dropdown.selected]);
 	}
 
 	onSelectionChange(itemIdx)
Index: source/ps/Game.cpp
===================================================================
--- source/ps/Game.cpp
+++ source/ps/Game.cpp
@@ -221,8 +221,13 @@
 	scriptInterface.GetProperty(attribs, "mapType", mapType);
 
 	float speed;
-	if (scriptInterface.HasProperty(attribs, "gameSpeed") && scriptInterface.GetProperty(attribs, "gameSpeed", speed))
-		SetSimRate(speed);
+	if (scriptInterface.HasProperty(attribs, "gameSpeed"))
+	{
+		if (scriptInterface.GetProperty(attribs, "gameSpeed", speed))
+			SetSimRate(speed);
+		else
+			LOGERROR("GameSpeed could not be parsed.");
+	}
 
 	LDR_BeginRegistering();