diff --git a/packages/lib/src/ModStore.ts b/packages/lib/src/ModStore.ts
index 1819e645..e53fdb39 100644
--- a/packages/lib/src/ModStore.ts
+++ b/packages/lib/src/ModStore.ts
@@ -1,8 +1,10 @@
 import fs from "fs-extra";
 import path from "path";
+import { Static } from "@sinclair/typebox";
 import { logger } from "./logging";
 import { ModInfo } from "./data";
 import TypedEventEmitter from "./TypedEventEmitter";
+import { safeOutputFile } from "./file_ops";
 
 export interface ModStoreEvents {
 	/** A stored mod was created, updated or deleted */
@@ -74,6 +76,21 @@ export default class ModStore extends TypedEventEmitter<keyof ModStoreEvents, Mo
 	}
 
 	static async fromDirectory(modsDirectory: string) {
+		type ModInfoCache = Static<typeof ModInfo.jsonSchema>[];
+		const cacheFilename = path.join(modsDirectory, "mod-info-cache.json");
+		let cache = new Map<string, ModInfo>();
+		try {
+			const content = await fs.readFile(cacheFilename, "utf8");
+			cache = new Map((JSON.parse(content) as ModInfoCache).map(item => {
+				const mod = ModInfo.fromJSON(item);
+				return [mod.filename, mod];
+			}));
+		} catch (err: any) {
+			if (err.code !== "ENOENT") {
+				logger.warn(`Error loading ${cacheFilename}:\n${err.stack}`);
+			}
+		}
+
 		const files = new Map<string, ModInfo>();
 		for (let entry of await fs.readdir(modsDirectory, { withFileTypes: true })) {
 			if (entry.isDirectory()) {
@@ -81,10 +98,23 @@ export default class ModStore extends TypedEventEmitter<keyof ModStoreEvents, Mo
 				continue;
 			}
 
+			if (!entry.name.toLowerCase().endsWith(".zip")) {
+				continue;
+			}
+
 			if (entry.name.toLowerCase().endsWith(".tmp.zip")) {
 				continue;
 			}
 
+			const cachedModInfo = cache.get(entry.name);
+			if (cachedModInfo) {
+				const stat = await fs.stat(path.join(modsDirectory, entry.name));
+				if (cachedModInfo.mtimeMs === stat.mtimeMs) {
+					files.set(cachedModInfo.filename, cachedModInfo);
+					continue;
+				}
+			}
+
 			logger.info(`Loading info for Mod ${entry.name}`);
 			let modInfo: ModInfo;
 			try {
@@ -96,6 +126,12 @@ export default class ModStore extends TypedEventEmitter<keyof ModStoreEvents, Mo
 			files.set(modInfo.filename, modInfo);
 		}
 
+		if (files.size) {
+			logger.info(`Loaded info for ${files.size} mods`);
+			const content: ModInfoCache = [...files.values()].map(mod => mod.toJSON());
+			await safeOutputFile(cacheFilename, JSON.stringify(content));
+		}
+
 		return new this(modsDirectory, files);
 	}
 }
diff --git a/packages/lib/src/data/ModInfo.ts b/packages/lib/src/data/ModInfo.ts
index b555f0bb..e29db8d3 100644
--- a/packages/lib/src/data/ModInfo.ts
+++ b/packages/lib/src/data/ModInfo.ts
@@ -116,6 +116,11 @@ export default class ModInfo {
 	 */
 	size = 0;
 
+	/**
+	 * Last modification time of the file.
+	 */
+	mtimeMs = 0;
+
 	/**
 	 * SHA1 hash of this mod
 	 */
@@ -147,6 +152,7 @@ export default class ModInfo {
 	static jsonSchema = Type.Object({
 		...this.infoJsonSchema.properties,
 		"size": Type.Optional(Type.Integer()),
+		"mtime_ms": Type.Optional(Type.Number()),
 		"sha1": Type.Optional(Type.String()),
 		"updated_at_ms": Type.Optional(Type.Number()),
 		"is_deleted": Type.Optional(Type.Boolean()),
@@ -170,6 +176,7 @@ export default class ModInfo {
 
 		// Additional data
 		if (json.size) { modInfo.size = json.size; }
+		if (json.mtime_ms) { modInfo.mtimeMs = json.mtime_ms; }
 		if (json.sha1) { modInfo.sha1 = json.sha1; }
 		if (json.updated_at_ms) { modInfo.updatedAtMs = json.updated_at_ms; }
 		if (json.is_deleted) { modInfo.isDeleted = json.is_deleted; }
@@ -192,6 +199,7 @@ export default class ModInfo {
 			json.dependencies = this.dependencies;
 		}
 		if (this.size) { json.size = this.size; }
+		if (this.mtimeMs) { json.mtime_ms = this.mtimeMs; }
 		if (this.sha1) { json.sha1 = this.sha1; }
 		if (this.updatedAtMs) { json.updated_at_ms = this.updatedAtMs; }
 		if (this.isDeleted) { json.is_deleted = this.isDeleted; }
@@ -229,6 +237,7 @@ export default class ModInfo {
 
 			size: stat.size,
 			sha1: await libHash.hashFile(modPath),
+			mtime_ms: stat.mtimeMs,
 			updated_at_ms: stat.mtimeMs,
 			is_deleted: false,
 		});
diff --git a/test/integration/clusterio.js b/test/integration/clusterio.js
index 4fe1f626..acf69b94 100644
--- a/test/integration/clusterio.js
+++ b/test/integration/clusterio.js
@@ -1054,6 +1054,7 @@ describe("Integration of Clusterio", function() {
 					"factorioVersion: 1.1\n" +
 					"dependencies:\n" +
 					`size: ${stat.size}\n` +
+					`mtimeMs: ${stat.mtimeMs}\n` +
 					`sha1: ${hash}\n` +
 					`updatedAtMs: ${stat.mtimeMs}\n` +
 					"isDeleted: false\n",
diff --git a/test/lib/data/ModInfo.js b/test/lib/data/ModInfo.js
index 50e104db..9e8d6c65 100644
--- a/test/lib/data/ModInfo.js
+++ b/test/lib/data/ModInfo.js
@@ -33,6 +33,7 @@ describe("lib/data/ModInfo", function() {
 			check(ModInfo.fromJSON({ dependencies: ["UltraMod", "SuperLib >= 1.00", "! bad-mod"] }));
 			check(ModInfo.fromJSON({ filename: "MyMod_1.0.0.zip" }));
 			check(ModInfo.fromJSON({ size: 1024 }));
+			check(ModInfo.fromJSON({ mtime_ms: new Date(2024, 0, 1).getTime() }));
 			check(ModInfo.fromJSON({ sha1: "verified-as-MyMod" }));
 			check(ModInfo.fromJSON({ is_deleted: true }));
 
@@ -49,6 +50,7 @@ describe("lib/data/ModInfo", function() {
 				dependencies: ["UltraMod", "SuperLib >= 1.00", "! bad-mod"],
 				filename: "MyMod_1.0.0.zip",
 				size: 1024,
+				mtime_ms: new Date(2024, 0, 1).getTime(),
 				sha1: "verified-as-MyMod",
 				is_deleted: true,
 			}));
@@ -92,6 +94,7 @@ describe("lib/data/ModInfo", function() {
 					dependencies: [],
 					filename: "empty_mod_1.0.0.zip",
 					size: stat.size,
+					mtime_ms: stat.mtimeMs,
 					updated_at_ms: stat.mtimeMs,
 					sha1: hash,
 				})