diff --git a/packages/lib/src/config/definitions.ts b/packages/lib/src/config/definitions.ts
index 798f90b3..dc4ca4d9 100644
--- a/packages/lib/src/config/definitions.ts
+++ b/packages/lib/src/config/definitions.ts
@@ -3,7 +3,7 @@ import * as classes from "./classes";
 import * as validate from "./validators";
 import type { PluginNodeEnvInfo, PluginWebpackEnvInfo } from "../plugin";
 import { Static } from "@sinclair/typebox";
-import { isTargetVersion } from "../data";
+import { isTargetVersion } from "../data/version";
 
 type configFromJSON<T> = (...args: Parameters<typeof classes.Config.fromJSON>) => T;
 type configFromFile<T> = (...args: Parameters<typeof classes.Config.fromFile>) => Promise<T>;
@@ -574,7 +574,7 @@ export class InstanceConfig extends classes.Config<InstanceConfigFields> {
 			initialValue: 5,
 			extendedValidation: function(value, config) {
 				const factorioSettings = config.get("factorio.settings");
-				const autosaveSlots = factorioSettings.autosave_slot;
+				const autosaveSlots = factorioSettings.autosave_slots;
 				if (typeof autosaveSlots === "number" && value < autosaveSlots) {
 					throw new Error("Value cannot be less than the number of autosave slots");
 				}
diff --git a/packages/lib/src/config/validators.ts b/packages/lib/src/config/validators.ts
index d4f1dabd..fa26c7c1 100644
--- a/packages/lib/src/config/validators.ts
+++ b/packages/lib/src/config/validators.ts
@@ -1,4 +1,4 @@
-import path from "node:path";
+import path from "path";
 
 /** Combine multiple validators into a single one. */
 export function all<V, C> (
diff --git a/packages/web_ui/src/components/BaseConfigTree.tsx b/packages/web_ui/src/components/BaseConfigTree.tsx
index 07e3c6ab..dc9e94c5 100644
--- a/packages/web_ui/src/components/BaseConfigTree.tsx
+++ b/packages/web_ui/src/components/BaseConfigTree.tsx
@@ -391,6 +391,18 @@ function computeTreeData(
 					help={errorFields.get(fieldName)}
 					tooltip={def.description}
 					valuePropName={def.type === "boolean" ? "checked" : "value"}
+					rules={[{
+						validator: function(_, fieldValue) {
+							if (def.extendedValidation) {
+								try {
+									def.extendedValidation(fieldValue, config);
+								} catch (err: any) {
+									return Promise.reject(err);
+								}
+							}
+							return Promise.resolve();
+						},
+					}]}
 				>
 					{renderInput(control.inputComponents, def, !canWrite)}
 				</Form.Item>;