diff --git a/assets/css/styles.css b/assets/css/styles.css
index 2ab9fc1..0c22ccf 100755
--- a/assets/css/styles.css
+++ b/assets/css/styles.css
@@ -179,7 +179,7 @@ div#readOnlyBlocklyCode {
         margin-right: auto;
     }
     /* robot ID label */
-    span.input-group-addon {
+    span.input-group-text {
         font-size: 4.5vw;
         font-weight: bold;
         padding: 0.5vw 1vw !important;