diff --git a/it/content/src/main/content/jcr_root/content/forms/af/core-components-it/samples/fileinput/fileinputv4/basic/.content.xml b/it/content/src/main/content/jcr_root/content/forms/af/core-components-it/samples/fileinput/fileinputv4/basic/.content.xml
index fd4851bff2..7133638f9e 100644
--- a/it/content/src/main/content/jcr_root/content/forms/af/core-components-it/samples/fileinput/fileinputv4/basic/.content.xml
+++ b/it/content/src/main/content/jcr_root/content/forms/af/core-components-it/samples/fileinput/fileinputv4/basic/.content.xml
@@ -108,6 +108,7 @@
                     jcr:title="File Input - 7"
                     sling:resourceType="core/fd/components/form/fileinput/v4/fileinput"
                     accept="[audio/*, video/*, image/*, text/*, application/pdf,.ifc]"
+                    acceptMessage="This file type is not supported!"
                     fieldType="file-input"
                     readOnly="{Boolean}false"
                     name="fileinput7"
diff --git a/ui.af.apps/src/main/content/jcr_root/apps/core/fd/components/form/fileinput/v4/fileinput/clientlibs/site/js/fileinputwidget.js b/ui.af.apps/src/main/content/jcr_root/apps/core/fd/components/form/fileinput/v4/fileinput/clientlibs/site/js/fileinputwidget.js
index 91708f50f0..a94441a5ec 100644
--- a/ui.af.apps/src/main/content/jcr_root/apps/core/fd/components/form/fileinput/v4/fileinput/clientlibs/site/js/fileinputwidget.js
+++ b/ui.af.apps/src/main/content/jcr_root/apps/core/fd/components/form/fileinput/v4/fileinput/clientlibs/site/js/fileinputwidget.js
@@ -191,7 +191,7 @@ if (typeof window.FileInputWidget === 'undefined') {
             const messages = {
                 [this.invalidFeature.SIZE]: customMessages.maxFileSize || FormView.LanguageUtils.getTranslatedString(this.lang, "FileSizeGreater", [fileNames, this.options.maxFileSize]),
                 [this.invalidFeature.NAME]: customMessages.invalidFileName || FormView.LanguageUtils.getTranslatedString(this.lang, "FileNameInvalid", [fileNames]),
-                [this.invalidFeature.MIMETYPE]: customMessages.invalidMimeType || FormView.LanguageUtils.getTranslatedString(this.lang, "FileMimeTypeInvalid", [fileNames]),
+                [this.invalidFeature.MIMETYPE]: customMessages.accept || FormView.LanguageUtils.getTranslatedString(this.lang, "FileMimeTypeInvalid", [fileNames]),
                 [this.invalidFeature.SIZE_ZERO]: customMessages.zeroFileSize || FormView.LanguageUtils.getTranslatedString(this.lang, "FileSizeZero", [fileNames])
             };
             return messages[invalidFeature];
diff --git a/ui.frontend/src/view/FormFileInputWidgetBase.js b/ui.frontend/src/view/FormFileInputWidgetBase.js
index e0a4d52097..1589cd0f82 100644
--- a/ui.frontend/src/view/FormFileInputWidgetBase.js
+++ b/ui.frontend/src/view/FormFileInputWidgetBase.js
@@ -340,7 +340,7 @@ class FormFileInputWidgetBase {
             const messages = {
                 [this.invalidFeature.SIZE]: customMessages.maxFileSize || FormView.LanguageUtils.getTranslatedString(this.lang, "FileSizeGreater", [fileName, this.options.maxFileSize]),
                 [this.invalidFeature.NAME]: customMessages.invalidFileName || FormView.LanguageUtils.getTranslatedString(this.lang, "FileNameInvalid", [fileName]),
-                [this.invalidFeature.MIMETYPE]: customMessages.invalidMimeType || FormView.LanguageUtils.getTranslatedString(this.lang, "FileMimeTypeInvalid", [fileName])
+                [this.invalidFeature.MIMETYPE]: customMessages.accept || FormView.LanguageUtils.getTranslatedString(this.lang, "FileMimeTypeInvalid", [fileName])
             };
         
             alert(messages[invalidFeature]);
diff --git a/ui.tests/test-module/specs/fileinput/fileinputv4.runtime.cy.js b/ui.tests/test-module/specs/fileinput/fileinputv4.runtime.cy.js
index 428f17e1c1..85df0a2ab9 100644
--- a/ui.tests/test-module/specs/fileinput/fileinputv4.runtime.cy.js
+++ b/ui.tests/test-module/specs/fileinput/fileinputv4.runtime.cy.js
@@ -272,6 +272,16 @@ describe('Click on button tag (V-4)', () => {
         });
     });
 
+    it('should display a custom error message configured by the user for unsupported file type', () => {
+        const [id, fieldView] = Object.entries(formContainer._fields)[6];
+        const model = formContainer._model.getElement(id);
+        const fileInput = 'input[name=\'fileinput7\']';
+        cy.attachFile(fileInput, ['sample.afe']);
+        cy.on('window:alert', (alertText) => {
+            expect(alertText).to.equal(model.getState().constraintMessages.accept);
+        });
+    });
+
     it('file when uploaded again should give actual size', () => {
         let sampleFileNames = ['sample.svg'];
         const fileInput = "input[name='fileinput2']";