diff --git a/browser/src/control/Control.UIManager.js b/browser/src/control/Control.UIManager.js
index 618e5ef2b..4eba645eb 100644
--- a/browser/src/control/Control.UIManager.js
+++ b/browser/src/control/Control.UIManager.js
@@ -1006,6 +1006,65 @@ L.Control.UIManager = L.Control.extend({
 		}
 	},
 
+	// Opens a yesno modal with configurable buttons.
+	showYesNoButton: function(id, title, message, yesButtonText, noButtonText, yesFunction, noFunction, cancellable) {
+		var dialogId = this.generateModalId(id);
+
+		var json = this._modalDialogJSON(id, title, cancellable, [
+			{
+				id:  dialogId + '-title',
+				type: 'fixedtext',
+				text: title,
+				hidden: !window.mode.isMobile()
+			},
+			{
+				id: dialogId + '-label',
+				type: 'fixedtext',
+				text: message
+			},
+			{
+				id: '',
+				type: 'buttonbox',
+				text: '',
+				enabled: true,
+				children: [
+					noButtonText ? {
+						id: dialogId + '-nobutton',
+						type: 'pushbutton',
+						text: noButtonText
+					} : { type: 'container' },
+					{
+						id: dialogId + '-yesbutton',
+						type: 'pushbutton',
+						text: yesButtonText,
+					}
+				],
+				vertical: false,
+				layoutstyle: 'end'
+			},
+		]);
+
+		this.showModal(json,
+		[
+			{
+				id: dialogId + '-nobutton',
+				func: function() {
+					if (typeof noFunction === 'function')
+						noFunction();
+					this.closeModal(dialogId);
+				}.bind(this)
+			},
+			{
+				id: dialogId + '-yesbutton',
+				func: function() {
+					if (typeof yesFunction === 'function')
+						yesFunction();
+					this.closeModal(dialogId);
+				}.bind(this)
+			}
+		]);
+	},
+
 	/// shows simple confirm modal (message + (cancel + ok) button)
 	/// id - id of a dialog
 	/// title - title of a dialog
diff --git a/browser/src/control/Permission.js b/browser/src/control/Permission.js
index 21baa6b86..3e35a1623 100644
--- a/browser/src/control/Permission.js
+++ b/browser/src/control/Permission.js
@@ -2,7 +2,7 @@
 /*
  * Document permission handler
  */
-/* global app $ _ vex */
+/* global app $ _ */
 L.Map.include({
 	readonlyStartingFormats: {
 		'txt': { canEdit: true, odfFormat: 'odt' },
@@ -148,30 +148,31 @@ L.Map.include({
 	_switchToEditMode: function () {
 		// This will be handled by the native mobile app instead
 		if (this._shouldStartReadOnly() && !window.ThisIsAMobileApp) {
-			var that = this;
 			var fileName = this['wopi'].BaseFileName;
 			var extension = this._getFileExtension(fileName);
 			var extensionInfo = this.readonlyStartingFormats[extension];
 
-			var buttonList = [];
-			if (!this['wopi'].UserCanNotWriteRelative) {
-				buttonList.push($.extend({}, vex.dialog.buttons.YES, { text: _('Save as ODF format') }));
-			}
-			buttonList.push($.extend({}, vex.dialog.buttons.NO, { text: extensionInfo.canEdit ? _('Continue editing') : _('Continue read only')}));
+			var yesButtonText = !this['wopi'].UserCanNotWriteRelative ? _('Save as ODF format'): null;
+			var noButtonText = extensionInfo.canEdit ? _('Continue editing') : _('Continue read only');
 
-			vex.dialog.open({
-				message: _('This document may contain formatting or content that cannot be saved in the current file format.'),
-				overlayClosesOnClick: false,
-				callback: L.bind(function (value) {
-					if (value) {
-						// offer save-as instead
-						this._offerSaveAs();
-					} else {
-						this._proceedEditMode();
-					}
-				}, that),
-				buttons: buttonList
-			});
+			if (!yesButtonText) {
+				yesButtonText = noButtonText;
+				noButtonText = null;
+			}
+
+			var yesFunction = !noButtonText ? function() { this._proceedEditMode(); }.bind(this) : function() { this._offerSaveAs(); }.bind(this);
+			var noFunction = function() { this._proceedEditMode(); }.bind(this);
+
+			this.uiManager.showYesNoButton(
+				'switch-to-edit-mode-modal', // id.
+				'', // Title.
+				_('This document may contain formatting or content that cannot be saved in the current file format.'), // Message.
+				yesButtonText,
+				noButtonText,
+				yesFunction,
+				noFunction,
+				false // Cancellable.
+			);
 		} else {
 			this._proceedEditMode();
 		}
diff --git a/cypress_test/integration_tests/desktop/calc/open_different_file_types_spec.js b/cypress_test/integration_tests/desktop/calc/open_different_file_types_spec.js
index 8238c4656..e94d67e35 100644
--- a/cypress_test/integration_tests/desktop/calc/open_different_file_types_spec.js
+++ b/cypress_test/integration_tests/desktop/calc/open_different_file_types_spec.js
@@ -83,7 +83,7 @@ describe('Open different file types', function () {
 			.should('be.visible')
 			.click();
 
-		cy.get('.vex-content button').click();
+		cy.get('#modal-dialog-switch-to-edit-mode-modal-yesbutton').click();
 
 		assertData();
 	});
@@ -94,19 +94,17 @@ describe('Open different file types', function () {
 		cy.get('#mobile-edit-button').should('be.visible')
 			.click();
 
-		cy.get('.vex-overlay').should('be.visible');
+		cy.get('#modal-dialog-switch-to-edit-mode-modal-overlay').should('be.visible');
 
-		cy.get('.vex-dialog-message')
+		cy.get('#modal-dialog-switch-to-edit-mode-modal-label')
 			.should('have.text', 'This document may contain formatting or content that cannot be saved in the current file format.');
 
-		cy.get('.vex-dialog-buttons button')
+		cy.get('#modal-dialog-switch-to-edit-mode-modal-yesbutton')
 			.should('have.text', 'Continue read only')
 			.click();
 
 		cy.get('#PermissionMode').should('be.visible')
 			.should('have.text', ' Read-only ');
-
-		cy.get('.vex-overlay').should('be.visible');
 	});
 
 	it('Open xlsm file' ,function() {