diff --git a/lib/ModuleLayerCache.js b/lib/ModuleLayerCache.js
index 2708ef1824c..f8f1ec3fcf2 100644
--- a/lib/ModuleLayerCache.js
+++ b/lib/ModuleLayerCache.js
@@ -70,7 +70,9 @@ class ModuleLayerCache {
 	 * @param {string | Buffer} value The value to store in the cache.
 	 */
 	set(key, value) {
-		const weakMapKey = new WeakMapKey(key);
+		const weakMapKey = this.weakMapKeys.has(key)
+			? this.weakMapKeys.get(key)
+			: new WeakMapKey(key);
 		this.weakMapKeys.set(key, weakMapKey);
 		this.cachedValues.set(weakMapKey, value);
 	}
diff --git a/lib/NormalModule.js b/lib/NormalModule.js
index 374fd66df2a..066095b7eb0 100644
--- a/lib/NormalModule.js
+++ b/lib/NormalModule.js
@@ -232,8 +232,8 @@ makeSerializable(
 /** @type {WeakMap<Compilation, NormalModuleCompilationHooks>} */
 const compilationHooksMap = new WeakMap();
 
-/** @type {ModuleLayerCache} */
-const moduleLayerCache = new ModuleLayerCache();
+/** @type {WeakMap<Object, ModuleLayerCache>} */
+const cachedModuleLayerCaches = new WeakMap();
 
 class NormalModule extends Module {
 	/**
@@ -784,6 +784,31 @@ class NormalModule extends Module {
 	 * @returns {Source} the created source
 	 */
 	createSource(context, content, sourceMap, associatedObjectForCache) {
+		// If this module exists in a layer, try to reuse the value for the
+		// source string so it is not duplicated in multiple modules.
+		if (this.layer && this.userRequest) {
+			let moduleLayerCache = cachedModuleLayerCaches.get(
+				associatedObjectForCache
+			);
+			if (moduleLayerCache) {
+				moduleLayerCache = new ModuleLayerCache();
+				cachedModuleLayerCaches.set(associatedObjectForCache, moduleLayerCache);
+			}
+			if (moduleLayerCache.has(this.userRequest)) {
+				const cachedSource = moduleLayerCache.get(this.userRequest);
+				if (
+					(Buffer.isBuffer(content) &&
+						Buffer.isBuffer(cachedSource) &&
+						content.equals(cachedSource)) ||
+					content === cachedSource
+				) {
+					content = cachedSource;
+				}
+			} else {
+				moduleLayerCache.set(this.userRequest, content);
+			}
+		}
+
 		if (Buffer.isBuffer(content)) {
 			return new RawSource(content);
 		}
@@ -871,24 +896,6 @@ class NormalModule extends Module {
 				return callback(error);
 			}
 
-			// If this module exists in a layer, try to reuse the value for the
-			// source string so it is not duplicated in multiple modules.
-			if (this.layer && this.request) {
-				if (moduleLayerCache.has(this.request)) {
-					const cachedSource = moduleLayerCache.get(this.request);
-					if (
-						(Buffer.isBuffer(source) &&
-							Buffer.isBuffer(cachedSource) &&
-							source.equals(cachedSource)) ||
-						source === cachedSource
-					) {
-						source = cachedSource;
-					}
-				} else {
-					moduleLayerCache.set(this.request, source);
-				}
-			}
-
 			this._source = this.createSource(
 				/** @type {string} */ (options.context),
 				this.binary ? asBuffer(source) : asString(source),
diff --git a/lib/json/JsonModulesPlugin.js b/lib/json/JsonModulesPlugin.js
index 5b998482870..0d60d1e88a3 100644
--- a/lib/json/JsonModulesPlugin.js
+++ b/lib/json/JsonModulesPlugin.js
@@ -44,7 +44,7 @@ class JsonModulesPlugin {
 					.tap(PLUGIN_NAME, parserOptions => {
 						validate(parserOptions);
 
-						return new JsonParser(parserOptions);
+						return new JsonParser(parserOptions, compilation);
 					});
 				normalModuleFactory.hooks.createGenerator
 					.for(JSON_MODULE_TYPE)
diff --git a/lib/json/JsonParser.js b/lib/json/JsonParser.js
index b3bc4277e73..fcd24fc7687 100644
--- a/lib/json/JsonParser.js
+++ b/lib/json/JsonParser.js
@@ -20,16 +20,18 @@ const JsonData = require("./JsonData");
 
 const getParseJson = memoize(() => require("json-parse-even-better-errors"));
 
-/** @type {ModuleLayerCache} */
-const moduleLayerCache = new ModuleLayerCache();
+/** @type {WeakMap<Object, ModuleLayerCache>} */
+const cachedModuleLayerCaches = new WeakMap();
 
 class JsonParser extends Parser {
 	/**
 	 * @param {JsonModulesPluginParserOptions} options parser options
+	 * @param {Object} associatedObjectForCache An object to associate cached data with.
 	 */
-	constructor(options) {
+	constructor(options, associatedObjectForCache) {
 		super();
 		this.options = options || {};
+		this.associatedObjectForCache = associatedObjectForCache;
 	}
 
 	/**
@@ -61,14 +63,24 @@ class JsonParser extends Parser {
 		// If the module is associated with a layer, try to reuse cached data instead
 		// of duplicating the data multiple times.
 		const module = state.module;
-		if (module && module.request && module.layer && Buffer.isBuffer(data)) {
-			if (moduleLayerCache.has(module.request)) {
-				const cachedData = moduleLayerCache.get(module.request);
+		if (module && module.userRequest && module.layer && Buffer.isBuffer(data)) {
+			let moduleLayerCache = cachedModuleLayerCaches.get(
+				this.associatedObjectForCache
+			);
+			if (moduleLayerCache) {
+				moduleLayerCache = new ModuleLayerCache();
+				cachedModuleLayerCaches.set(
+					this.associatedObjectForCache,
+					moduleLayerCache
+				);
+			}
+			if (moduleLayerCache.has(module.userRequest)) {
+				const cachedData = moduleLayerCache.get(module.userRequest);
 				if (Buffer.isBuffer(cachedData) && data.equals(cachedData)) {
 					data = cachedData;
 				}
 			} else {
-				moduleLayerCache.set(module.request, data);
+				moduleLayerCache.set(module.userRequest, data);
 			}
 		}