diff --git a/packages/core/src/browser/dialogs.ts b/packages/core/src/browser/dialogs.ts
index a8e626b608827..8854573c61a25 100644
--- a/packages/core/src/browser/dialogs.ts
+++ b/packages/core/src/browser/dialogs.ts
@@ -166,8 +166,10 @@ export abstract class AbstractDialog<T> extends BaseWidget {
         container.classList.add('dialogBlock');
         if (props.maxWidth === undefined) {
             container.setAttribute('style', 'max-width: none');
-        } else {
+        } else if (props.maxWidth < 400) {
             container.setAttribute('style', `max-width: ${props.maxWidth}px; min-width: 0px`);
+        } else {
+            container.setAttribute('style', `max-width: ${props.maxWidth}px`);
         }
         this.node.appendChild(container);
 
diff --git a/packages/keymaps/src/browser/keybindings-widget.tsx b/packages/keymaps/src/browser/keybindings-widget.tsx
index 27991c71b8bd8..107d1315970f6 100644
--- a/packages/keymaps/src/browser/keybindings-widget.tsx
+++ b/packages/keymaps/src/browser/keybindings-widget.tsx
@@ -577,6 +577,7 @@ export class KeybindingWidget extends ReactWidget implements StatefulWidget {
         const oldKeybinding = item.keybinding;
         const dialog = new EditKeybindingDialog({
             title: nls.localize('theia/keymaps/editKeybindingTitle', 'Edit Keybinding for {0}', command),
+            maxWidth: 400,
             initialValue: oldKeybinding?.keybinding,
             validate: newKeybinding => this.validateKeybinding(command, oldKeybinding?.keybinding, newKeybinding),
         }, this.keymapsService, item);
diff --git a/packages/workspace/src/browser/workspace-commands.ts b/packages/workspace/src/browser/workspace-commands.ts
index 6f1c944f9972a..04c9ed8b17290 100644
--- a/packages/workspace/src/browser/workspace-commands.ts
+++ b/packages/workspace/src/browser/workspace-commands.ts
@@ -235,6 +235,7 @@ export class WorkspaceCommandContribution implements CommandContribution {
 
                     const dialog = new WorkspaceInputDialog({
                         title: nls.localizeByDefault('New File...'),
+                        maxWidth: 400,
                         parentUri: parentUri,
                         initialValue: vacantChildUri.path.base,
                         placeholder: nls.localize('theia/workspace/newFilePlaceholder', 'File Name'),
@@ -260,6 +261,7 @@ export class WorkspaceCommandContribution implements CommandContribution {
                     const vacantChildUri = FileSystemUtils.generateUniqueResourceURI(parent, targetUri, true);
                     const dialog = new WorkspaceInputDialog({
                         title: nls.localizeByDefault('New Folder...'),
+                        maxWidth: 400,
                         parentUri: parentUri,
                         initialValue: vacantChildUri.path.base,
                         placeholder: nls.localize('theia/workspace/newFolderPlaceholder', 'Folder Name'),
@@ -285,6 +287,7 @@ export class WorkspaceCommandContribution implements CommandContribution {
                     const oldName = uri.path.base;
                     const dialog = new SingleTextInputDialog({
                         title: nls.localizeByDefault('Rename'),
+                        maxWidth: 400,
                         initialValue: oldName,
                         initialSelectionRange: {
                             start: 0,