diff --git a/test/lib/server/middleware/serveResources.js b/test/lib/server/middleware/serveResources.js
index 90e64e65..24a430c6 100644
--- a/test/lib/server/middleware/serveResources.js
+++ b/test/lib/server/middleware/serveResources.js
@@ -529,7 +529,7 @@ test.serial("Check if utf8 characters are correctly processed in version replace
 	});
 });
 
-test.serial("Check if manifest.json file is served properly by using manifestTransformer", async (t) => {
+test.serial("manifestTransformer: request manifest.json with auto generated supported locales", async (t) => {
 	t.plan(4);
 
 	const readerWriter = resourceFactory.createAdapter({virBasePath: "/"});
@@ -618,3 +618,262 @@ test.serial("Check if manifest.json file is served properly by using manifestTra
 	t.is(setStringSpy.callCount, 1);
 	t.is(setHeaderSpy.getCall(0).lastArg, "application/json; charset=UTF-8");
 });
+
+test.serial("manifestTransformer: manifest.json with manual defined supported locales", async (t) => {
+	t.plan(4);
+
+	const readerWriter = resourceFactory.createAdapter({virBasePath: "/"});
+
+	const input = `{
+  "_version": "1.58.0",
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+		  "supportedLocales": ["fr", "de"],
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+	const expected = `{
+  "_version": "1.58.0",
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+		  "supportedLocales": ["fr", "de"],
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+
+	const project = {
+		getNamespace: () => "sap.ui.demo.app",
+		getVersion: () => "1.0.0"
+	};
+
+	const resource = await writeResource(readerWriter, "/manifest.json", 1024 * 1024,
+		input, "utf8", project
+	);
+	const setStringSpy = sinon.spy(resource, "setString");
+
+	const serveResourcesMiddlewareWithMock = t.context.serveResourcesMiddlewareWithMock =
+		await esmock.p("../../../../lib/middleware/serveResources", {
+			"@ui5/fs/fsInterface": sinon.stub().returns({
+				readdir(fsPath, callback) {
+					t.fail("fs.readdir should never be called");
+				}
+			})
+		});
+	const middleware = serveResourcesMiddlewareWithMock({
+		middlewareUtil: new MiddlewareUtil({graph: "graph", project: "project"}),
+		resources: {
+			all: readerWriter
+		}
+	});
+
+	const response = fakeResponse;
+
+	const setHeaderSpy = sinon.spy(response, "setHeader");
+	const req = {
+		url: "/manifest.json",
+		headers: {}
+	};
+	const next = function(err) {
+		throw new Error(`Next callback called with error: ${err.stack}`);
+	};
+
+	await middleware(req, response, next);
+	const content = await resource.getString();
+
+	t.is(content, expected);
+	t.is(setHeaderSpy.callCount, 2);
+	t.is(setStringSpy.callCount, 0);
+	t.is(setHeaderSpy.getCall(0).lastArg, "application/json; charset=UTF-8");
+});
+
+test.serial("manifestTransformer: no generation of supported locales " +
+	"if manifest.json version is below 1.21.0",
+async (t) => {
+	t.plan(4);
+
+	const readerWriter = resourceFactory.createAdapter({virBasePath: "/"});
+
+	const input = `{
+  "_version": "1.20.0",
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+	const expected = `{
+  "_version": "1.20.0",
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+
+	const project = {
+		getNamespace: () => "sap.ui.demo.app",
+		getVersion: () => "1.0.0"
+	};
+
+	const resource = await writeResource(readerWriter, "/manifest.json", 1024 * 1024,
+		input, "utf8", project
+	);
+	const setStringSpy = sinon.spy(resource, "setString");
+
+	const serveResourcesMiddlewareWithMock = t.context.serveResourcesMiddlewareWithMock =
+		await esmock.p("../../../../lib/middleware/serveResources", {
+			"@ui5/fs/fsInterface": sinon.stub().returns({
+				readdir(fsPath, callback) {
+					t.fail("fs.readdir should never be called");
+				}
+			})
+		});
+	const middleware = serveResourcesMiddlewareWithMock({
+		middlewareUtil: new MiddlewareUtil({graph: "graph", project: "project"}),
+		resources: {
+			all: readerWriter
+		}
+	});
+
+	const response = fakeResponse;
+
+	const setHeaderSpy = sinon.spy(response, "setHeader");
+	const req = {
+		url: "/manifest.json",
+		headers: {}
+	};
+	const next = function(err) {
+		throw new Error(`Next callback called with error: ${err.stack}`);
+	};
+
+	await middleware(req, response, next);
+	const content = await resource.getString();
+
+	t.is(content, expected);
+	t.is(setHeaderSpy.callCount, 2);
+	t.is(setStringSpy.callCount, 0);
+	t.is(setHeaderSpy.getCall(0).lastArg, "application/json; charset=UTF-8");
+});
+
+test.serial("manifestTransformer: no generation of supported locales " +
+	"if manifest.json version is not defined",
+async (t) => {
+	t.plan(4);
+
+	const readerWriter = resourceFactory.createAdapter({virBasePath: "/"});
+
+	const input = `{
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+	const expected = `{
+  "sap.app": {
+    "id": "sap.ui.demo.app"
+  },
+  "sap.ui5": {
+    "models": {
+      "i18n": {
+        "type": "sap.ui.model.resource.ResourceModel",
+        "settings": {
+          "bundleName": "sap.ui.demo.app.i18n.i18n",
+          "fallbackLocale": "de"
+        }
+      }
+    }
+  }
+}`;
+
+	const project = {
+		getNamespace: () => "sap.ui.demo.app",
+		getVersion: () => "1.0.0"
+	};
+
+	const resource = await writeResource(readerWriter, "/manifest.json", 1024 * 1024,
+		input, "utf8", project
+	);
+	const setStringSpy = sinon.spy(resource, "setString");
+
+	const serveResourcesMiddlewareWithMock = t.context.serveResourcesMiddlewareWithMock =
+		await esmock.p("../../../../lib/middleware/serveResources", {
+			"@ui5/fs/fsInterface": sinon.stub().returns({
+				readdir(fsPath, callback) {
+					t.fail("fs.readdir should never be called");
+				}
+			})
+		});
+	const middleware = serveResourcesMiddlewareWithMock({
+		middlewareUtil: new MiddlewareUtil({graph: "graph", project: "project"}),
+		resources: {
+			all: readerWriter
+		}
+	});
+
+	const response = fakeResponse;
+
+	const setHeaderSpy = sinon.spy(response, "setHeader");
+	const req = {
+		url: "/manifest.json",
+		headers: {}
+	};
+	const next = function(err) {
+		throw new Error(`Next callback called with error: ${err.stack}`);
+	};
+
+	await middleware(req, response, next);
+	const content = await resource.getString();
+
+	t.is(content, expected);
+	t.is(setHeaderSpy.callCount, 2);
+	t.is(setStringSpy.callCount, 0);
+	t.is(setHeaderSpy.getCall(0).lastArg, "application/json; charset=UTF-8");
+});