diff --git a/source/ps/GameSetup/GameSetup.cpp b/source/ps/GameSetup/GameSetup.cpp
index f91201f3d6..70ac83541a 100644
--- a/source/ps/GameSetup/GameSetup.cpp
+++ b/source/ps/GameSetup/GameSetup.cpp
@@ -934,6 +934,7 @@ bool Autostart(const CmdLineArgs& args)
 	/*
 	 * Handle various command-line options, for quick testing of various features:
 	 * -autostart=name					-- map name for scenario, or rms name for random map
+	 * -autostart-ai=1:dummybot			-- adds the dummybot AI to player 1
 	 * -autostart-playername=name		-- multiplayer player name
 	 * -autostart-host					-- multiplayer host mode
 	 * -autostart-players=2				-- number of players
@@ -1038,18 +1039,17 @@ bool Autostart(const CmdLineArgs& args)
 
 	// Set player data for AIs
 	//		attrs.settings = { PlayerData: [ { AI: ... }, ... ] }:
-
-	/*
-	 * Handle command-line options for AI:
-	 *  -autostart-ai=1:dummybot -autostart-ai=2:dummybot        -- adds the dummybot AI to players 1 and 2
-	 */
 	if (args.Has("autostart-ai"))
 	{
 		std::vector<CStr> aiArgs = args.GetMultiple("autostart-ai");
 		for (size_t i = 0; i < aiArgs.size(); ++i)
 		{
+			// Instead of overwriting existing player data, modify the array
 			CScriptVal player;
-			scriptInterface.Eval("({})", player);
+			if (!scriptInterface.GetPropertyInt(playerData.get(), i, player) || player.undefined())
+			{
+				scriptInterface.Eval("({})", player);
+			}
 
 			int playerID = aiArgs[i].BeforeFirst(":").ToInt();
 			CStr name = aiArgs[i].AfterFirst(":");
diff --git a/source/scriptinterface/ScriptInterface.cpp b/source/scriptinterface/ScriptInterface.cpp
index 258173c381..b56114c4f8 100644
--- a/source/scriptinterface/ScriptInterface.cpp
+++ b/source/scriptinterface/ScriptInterface.cpp
@@ -716,6 +716,17 @@ bool ScriptInterface::GetProperty_(jsval obj, const char* name, jsval& out)
 	return true;
 }
 
+bool ScriptInterface::GetPropertyInt_(jsval obj, int name, jsval& out)
+{
+	if (! JSVAL_IS_OBJECT(obj))
+		return false;
+	JSObject* object = JSVAL_TO_OBJECT(obj);
+
+	if (!JS_GetPropertyById(m->m_cx, object, INT_TO_JSID(name), &out))
+		return false;
+	return true;
+}
+
 bool ScriptInterface::HasProperty(jsval obj, const char* name)
 {
 	if (! JSVAL_IS_OBJECT(obj))
diff --git a/source/scriptinterface/ScriptInterface.h b/source/scriptinterface/ScriptInterface.h
index 6213ec666d..69f7e9dba1 100644
--- a/source/scriptinterface/ScriptInterface.h
+++ b/source/scriptinterface/ScriptInterface.h
@@ -190,9 +190,21 @@ public:
 	template<typename T>
 	bool SetPropertyInt(jsval obj, int name, const T& value, bool constant = false, bool enumerate = true);
 
+	/**
+	 * Get the named property on the given object.
+	 */
 	template<typename T>
 	bool GetProperty(jsval obj, const char* name, T& out);
 
+	/**
+	 * Get the integer-named property on the given object.
+	 */
+	template<typename T>
+	bool GetPropertyInt(jsval obj, int name, T& out);
+
+	/**
+	 * Check the named property has been defined on the given object.
+	 */
 	bool HasProperty(jsval obj, const char* name);
 
 	bool EnumeratePropertyNamesWithPrefix(jsval obj, const char* prefix, std::vector<std::string>& out);
@@ -311,6 +323,7 @@ private:
 	bool SetProperty_(jsval obj, const char* name, jsval value, bool readonly, bool enumerate);
 	bool SetPropertyInt_(jsval obj, int name, jsval value, bool readonly, bool enumerate);
 	bool GetProperty_(jsval obj, const char* name, jsval& value);
+	bool GetPropertyInt_(jsval obj, int name, jsval& value);
 	static bool IsExceptionPending(JSContext* cx);
 	static JSClass* GetClass(JSContext* cx, JSObject* obj);
 	static void* GetPrivate(JSContext* cx, JSObject* obj);
@@ -460,6 +473,15 @@ bool ScriptInterface::GetProperty(jsval obj, const char* name, T& out)
 	return FromJSVal(GetContext(), val, out);
 }
 
+template<typename T>
+bool ScriptInterface::GetPropertyInt(jsval obj, int name, T& out)
+{
+	jsval val;
+	if (! GetPropertyInt_(obj, name, val))
+		return false;
+	return FromJSVal(GetContext(), val, out);
+}
+
 template<typename T, typename CHAR>
 bool ScriptInterface::Eval(const CHAR* code, T& ret)
 {