diff --git a/css/converse.css b/css/converse.css
index dbe18486d..f68a341d0 100644
--- a/css/converse.css
+++ b/css/converse.css
@@ -645,6 +645,10 @@ span.spinner.hor_centered {
   border-right: 1px solid #176679;
   border-left: 1px solid #176679;
 }
+#conversejs .chat-message span::selection,
+#conversejs .chat-message::selection {
+  background-color: darkgrey;
+}
 #conversejs .chat-content {
   position: relative;
   padding: 4px;
diff --git a/less/converse.less b/less/converse.less
index 7c928cb47..06489c822 100644
--- a/less/converse.less
+++ b/less/converse.less
@@ -703,6 +703,11 @@ span.spinner.hor_centered {
     border-left:1px solid #176679;
 }
 
+#conversejs .chat-message span::selection,
+#conversejs .chat-message::selection {
+    background-color: darkgrey;
+}
+
 #conversejs .chat-content {
     position: relative;
     padding: 4px;