--- a/browser/themes/linux/devedition.css
+++ b/browser/themes/linux/devedition.css
@@ -20,16 +20,26 @@
 }
 
 :root[devtoolstheme="dark"] .findbar-closebutton:not(:hover),
 :root[devtoolstheme="dark"] #sidebar-header > .close-icon:not(:hover),
 .tab-close-button[selected]:not(:hover) {
   background-image: -moz-image-rect(url("chrome://global/skin/icons/close.svg"), 0, 80, 16, 64);
 }
 
+/* We're a dark-text lightweight theme (because there's only 1 lwtheme for the
+ * devedition theme) and so if we don't do anything, the text shadow will be
+ * white (to make black text more readable against variable backgrounds). But
+ * text is white in the dark devedition theme, and so we shouldn't have a
+ * white text-shadow.
+ */
+:root[devtoolstheme="dark"]:-moz-lwtheme {
+  text-shadow: none;
+}
+
 /* The menubar and tabs toolbar should match the devedition theme */
 #TabsToolbar,
 #toolbar-menubar {
   -moz-appearance: none !important;
 }
 #main-menubar {
   color: var(--chrome-color);
 }