diff --git a/css/modals/_dialog.scss b/css/modals/_dialog.scss
index d4fc8f5c3..88af1ce07 100644
--- a/css/modals/_dialog.scss
+++ b/css/modals/_dialog.scss
@@ -154,6 +154,14 @@
     &-error {
         margin-bottom: 8px;
     }
+
+    /**
+     * Override Atlaskit dropdown styling when in a modal because the dropdown
+     * backgrounds clash with the modal backgrounds.
+     */
+    .htclLc[data-role=droplistContent] {
+        border: 1px solid #455166;
+    }
 }
 .modal-dialog-footer {
     font-size: $modalButtonFontSize;