diff --git a/plugins/inventory_sync/info.js b/plugins/inventory_sync/info.js
index 30de703a..5c80e838 100644
--- a/plugins/inventory_sync/info.js
+++ b/plugins/inventory_sync/info.js
@@ -59,9 +59,6 @@ module.exports = {
 				"player_name": { type: "string" },
 				"inventory": { type: "object" },
 			},
-			responseProperties: {
-				"success": { type: "boolean" },
-			},
 		}),
 		download: new libLink.Request({
 			type: "inventory_sync:download",
@@ -80,7 +77,6 @@ module.exports = {
 			type: "inventory_sync:databaseStats",
 			links: ["control-master"],
 			permission: "inventory_sync.inventory.view",
-			requestProperties: {},
 			responseProperties: {
 				"database_size": { type: "integer" },
 				"database_entries": { type: "integer" },
diff --git a/plugins/inventory_sync/instance.js b/plugins/inventory_sync/instance.js
index 482343ae..e3a40c5d 100644
--- a/plugins/inventory_sync/instance.js
+++ b/plugins/inventory_sync/instance.js
@@ -12,16 +12,11 @@ const libLuaTools = require("@clusterio/lib/lua_tools");
  * @returns {String[]} Chunks
  */
 function chunkify(chunkSize, string) {
-	if (string.length <= chunkSize) {
-		return [string];
-	}
-	let chunk = string.substr(0, chunkSize);
-	return [chunk, ...chunkify(chunkSize, string.replace(chunk, ""))];
+	return string.match(new RegExp(`.{1,${chunkSize}}`, "g"));
 }
 
 class InstancePlugin extends libPlugin.BaseInstancePlugin {
 	async init() {
-		this.inventoryQueue = [];
 		this.instance.server.on("ipc-inventory_sync_upload", content => this.handleUpload(content)
 			.catch(err => this.logger.error(`Error handling ipc-inventory_sync_upload:\n${err.stack}`)));
 		this.instance.server.on("ipc-inventory_sync_download", content => this.handleDownload(content)
@@ -44,14 +39,15 @@ class InstancePlugin extends libPlugin.BaseInstancePlugin {
 			player_name: player.player_name,
 		});
 		if (response.new_player) {
-			await this.sendRcon(`/sc inventory_sync.welcome_new_player('${response.player_name}')`)
+			await this.sendRcon(`/sc inventory_sync.welcome_new_player('${response.player_name}')`);
 		} else if (response.inventory) {
 			const chunkSize = this.instance.config.get("inventory_sync.rcon_chunk_size");
 			const chunks = chunkify(chunkSize, JSON.stringify(response.inventory));
 			this.logger.verbose(`Sending inventory for ${player.player_name} in ${chunks.length} chunks`);
 			for (let i = 0; i < chunks.length; i++) {
 				// this.logger.verbose(`Sending chunk ${i+1} of ${chunks.length}`)
-				await this.sendRcon(`/sc inventory_sync.download_inventory('${response.player_name}', '${libLuaTools.escapeString(chunks[i])}', ${i + 1}, ${chunks.length})`);
+				await this.sendRcon(`/sc inventory_sync.download_inventory('${response.player_name}',` +
+					`'${libLuaTools.escapeString(chunks[i])}', ${i + 1}, ${chunks.length})`, true);
 			}
 		}
 	}
diff --git a/plugins/inventory_sync/master.js b/plugins/inventory_sync/master.js
index 91618d3b..31f2f262 100644
--- a/plugins/inventory_sync/master.js
+++ b/plugins/inventory_sync/master.js
@@ -9,12 +9,12 @@ async function loadDatabase(config, logger) {
 	logger.verbose(`Loading ${itemsPath}`);
 	try {
 		let content = await fs.readFile(itemsPath);
-		return JSON.parse(content);
+		return new Map(JSON.parse(content));
 
 	} catch (err) {
 		if (err.code === "ENOENT") {
 			logger.verbose("Creating new inventory database");
-			return {};
+			return new Map();
 		}
 		throw err;
 	}
@@ -24,7 +24,7 @@ async function saveDatabase(masterConfig, inventories, logger) {
 	if (inventories) {
 		let file = path.resolve(masterConfig.get("master.database_directory"), "inventories.json");
 		logger.verbose(`writing ${file}`);
-		let content = JSON.stringify(inventories);
+		let content = JSON.stringify(Array.from(inventories));
 		await fs.outputFile(file, content);
 	}
 }
@@ -41,17 +41,16 @@ class MasterPlugin extends libPlugin.BaseMasterPlugin {
 
 	async uploadRequestHandler(message) {
 		this.logger.verbose(`Saving inventory for ${message.data.player_name}`);
-		this.inventories[message.data.player_name] = message.data.inventory;
-
-		return { success: true };
+		this.inventories.set(message.data.player_name, message.data.inventory);
 	}
 
 	async downloadRequestHandler(message) {
 		this.logger.verbose(`Downloading inventory for ${message.data.player_name}`);
+		let inventory = this.inventories.get(message.data.player_name);
 		return {
 			player_name: message.data.player_name,
-			inventory: this.inventories[message.data.player_name] || {},
-			new_player: !this.inventories[message.data.player_name],
+			inventory: inventory || {},
+			new_player: !inventory,
 		};
 	}
 
@@ -61,18 +60,18 @@ class MasterPlugin extends libPlugin.BaseMasterPlugin {
 	}
 
 	async databaseStatsRequestHandler(message) {
-		let inventories = Object.keys(this.inventories)
+		let inventories = Array.from(this.inventories.keys())
 			.map(name => ({
 				name,
-				length: JSON.stringify(this.inventories[name]).length,
+				length: JSON.stringify(this.inventories.get(name)).length,
 			}))
 			.sort((a, b) => a.stringified.length - b.stringified.length);
 		return {
 			database_size: inventories.map(x => x.length).reduce((a, b) => b - a, 0),
 			database_entries: inventories.length,
 			largest_entry: {
-				name: inventories[0].name,
-				size: inventories[0].length,
+				name: inventories[0]?.name || "-",
+				size: inventories[0]?.length || 0,
 			},
 		};
 	}