diff --git a/pkgs/plt-web-pkgs/plt-web-lib/resources/css/gumby.css b/pkgs/plt-web-pkgs/plt-web-lib/resources/css/gumby.css
index b192731102..3e876769fe 100644
--- a/pkgs/plt-web-pkgs/plt-web-lib/resources/css/gumby.css
+++ b/pkgs/plt-web-pkgs/plt-web-lib/resources/css/gumby.css
@@ -18,7 +18,9 @@
 * Free to use under the MIT license.
 * http://www.opensource.org/licenses/mit-license.php
 */
-html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video { margin: 0; padding: 0; border: 0; font: inherit; font-size: 100%; vertical-align: baseline; }
+html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video { margin: 0; padding: 0; border: 0; font: inherit; font-size: 100%; vertical-align: baseline; }
+
+tt { margin: 0; padding: 0; border: 0; font-size: 100%; vertical-align: baseline; }
 
 b { font-weight: bold; }