diff --git a/addons/project/__manifest__.py b/addons/project/__manifest__.py
index ab64551b14f..6d630f43beb 100644
--- a/addons/project/__manifest__.py
+++ b/addons/project/__manifest__.py
@@ -81,6 +81,7 @@
             'project/static/src/js/portal_rating.js',
         ],
         'web.qunit_suite_tests': [
+            'project/static/src/project_sharing/components/portal_file_input/portal_file_input.js',
             'project/static/tests/**/*.js',
         ],
         'web.assets_tests': [
diff --git a/addons/project/static/tests/portal_components_tests.js b/addons/project/static/tests/portal_components_tests.js
new file mode 100644
index 00000000000..f447dfadc85
--- /dev/null
+++ b/addons/project/static/tests/portal_components_tests.js
@@ -0,0 +1,76 @@
+/** @odoo-module **/
+
+import { makeTestEnv } from "@web/../tests/helpers/mock_env";
+import {
+    editInput,
+    getFixture,
+    mount,
+    patchWithCleanup,
+} from "@web/../tests/helpers/utils";
+import { PortalFileInput } from "@project/project_sharing/components/portal_file_input/portal_file_input";
+import { registry } from "@web/core/registry";
+import { session } from "@web/session";
+import { makeFakeLocalizationService } from "@web/../tests/helpers/mock_services";
+
+const serviceRegistry = registry.category("services");
+
+let target;
+
+// -----------------------------------------------------------------------------
+// Helpers
+// -----------------------------------------------------------------------------
+
+async function createFileInput({ mockPost, mockAdd, props }) {
+    serviceRegistry.add("notification", {
+        start: () => ({
+            add: mockAdd || (() => {}),
+        }),
+    });
+    serviceRegistry.add("http", {
+        start: () => ({
+            post: mockPost || (() => {}),
+        }),
+    });
+    const env = await makeTestEnv();
+    await mount(PortalFileInput, target, { env, props });
+}
+
+// -----------------------------------------------------------------------------
+// Tests
+// -----------------------------------------------------------------------------
+
+QUnit.module("Project", ({ beforeEach }) => {
+    beforeEach(() => {
+        patchWithCleanup(odoo, { csrf_token: "dummy" });
+
+        target = getFixture();
+    });
+
+    QUnit.module("PortalComponents");
+
+    QUnit.test("uploading a file that is too heavy in portal will send a notification", async (assert) => {
+        serviceRegistry.add("localization", makeFakeLocalizationService());
+        patchWithCleanup(session, { max_file_upload_size: 2 });
+        await createFileInput({
+            props: {
+                onUpload(files) {
+                    assert.deepEqual(files, [null]);
+                },
+            },
+            mockAdd: (message) => {
+                assert.step("notification");
+                assert.strictEqual(
+                    message,
+                    "The selected file (4B) is over the maximum allowed file size (2B)."
+                );
+            },
+        });
+
+        const file = new File(["test"], "fake_file.txt", { type: "text/plain" });
+        await editInput(target, ".o_file_input input", file);
+        assert.verifySteps(
+            ["notification"],
+            "Only the notification will be triggered and the file won't be uploaded."
+        );
+    });
+});
diff --git a/addons/web/static/src/core/file_input/file_input.js b/addons/web/static/src/core/file_input/file_input.js
index c2a9badf00c..941cd64e2db 100644
--- a/addons/web/static/src/core/file_input/file_input.js
+++ b/addons/web/static/src/core/file_input/file_input.js
@@ -56,8 +56,8 @@ export class FileInput extends Component {
     }
 
     async uploadFiles(params) {
-        if (params.ufile.length) {
-            const fileSize = params.ufile[0].size;
+        if ((params.ufile && params.ufile.length) || params.file) {
+            const fileSize = (params.ufile && params.ufile[0].size) || params.file.size;
             if (!checkFileSize(fileSize, this.notification)) {
                 return null;
             }