diff --git a/src/skins/vector/css/themes/_dark.scss b/src/skins/vector/css/themes/_dark.scss
index e474d278c..c140f7079 100644
--- a/src/skins/vector/css/themes/_dark.scss
+++ b/src/skins/vector/css/themes/_dark.scss
@@ -142,6 +142,25 @@ $lightbox-border-color: #ffffff;
 // unused?
 $progressbar-color: #000;
 
+// XXX: copypasted from _base in order to pick up the right FG color...
+@define-mixin mx_DialogButton {
+    /* align images in buttons (eg spinners) */
+    vertical-align: middle;
+    border: 0px;
+    border-radius: 36px;
+    font-family: $font-family;
+    font-size: 14px;
+    color: $accent-fg-color;
+    background-color: $accent-color;
+    width: auto;
+    padding: 7px;
+    padding-left: 1.5em;
+    padding-right: 1.5em;
+    cursor: pointer;
+    display: inline-block;
+    outline: none;
+}
+
 // Nasty hacks to apply a filter to arbitrary monochrome artwork to make it
 // better match the theme.  Typically applied to dark grey 'off' buttons or
 // light grey 'on' buttons.