diff --git a/types/material-ui/index.d.ts b/types/material-ui/index.d.ts
index ce98d40903..47c124595e 100644
--- a/types/material-ui/index.d.ts
+++ b/types/material-ui/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for material-ui v0.17.5
+// Type definitions for material-ui v0.17.51
 // Project: https://github.com/callemall/material-ui
 // Definitions by: Nathan Brown <https://github.com/ngbrown>, Igor Belagorudsky <https://github.com/theigor>, Ali Taheri Moghaddar <https://github.com/alitaheri>, Oliver Herrmann <https://github.com/herrmanno>, Daniel Roth <https://github.com/DaIgeb>, Aurelién Allienne <https://github.com/allienna>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
@@ -1019,7 +1019,7 @@ declare namespace __MaterialUI {
         overlayStyle?: React.CSSProperties;
         style?: React.CSSProperties;
         swipeAreaWidth?: number;
-        width?: number;
+        width?: number | string;
         zDepth?: number;
     }
     export class Drawer extends React.Component<DrawerProps, {}> {
diff --git a/types/material-ui/material-ui-tests.tsx b/types/material-ui/material-ui-tests.tsx
index 87908cd6ec..a0d8d32d92 100644
--- a/types/material-ui/material-ui-tests.tsx
+++ b/types/material-ui/material-ui-tests.tsx
@@ -1662,7 +1662,7 @@ class DrawerOpenRightExample extends React.Component<{}, {open?: boolean}> {
           label="Toggle Drawer"
           onTouchTap={this.handleToggle}
         />
-                <Drawer width={200} openSecondary={true} open={this.state.open}>
+                <Drawer width="20%" openSecondary={true} open={this.state.open}>
                     <AppBar title="AppBar"/>
         </Drawer>
       </div>