diff --git a/theme/boost/scss/moodle/user.scss b/theme/boost/scss/moodle/user.scss
index 7554f4f58b7..701d8341cef 100644
--- a/theme/boost/scss/moodle/user.scss
+++ b/theme/boost/scss/moodle/user.scss
@@ -287,6 +287,7 @@
 
         select {
             min-width: 175px;
+            max-width: 90%;
         }
     }
 }
diff --git a/theme/bootstrapbase/less/moodle/user.less b/theme/bootstrapbase/less/moodle/user.less
index 4c33354ea79..c4df6c0d397 100644
--- a/theme/bootstrapbase/less/moodle/user.less
+++ b/theme/bootstrapbase/less/moodle/user.less
@@ -274,6 +274,7 @@
 
         select {
             min-width: 175px;
+            max-width: 90%;
         }
     }
 }
diff --git a/theme/bootstrapbase/style/moodle.css b/theme/bootstrapbase/style/moodle.css
index 2882943f0f9..425a617c4e0 100644
--- a/theme/bootstrapbase/style/moodle.css
+++ b/theme/bootstrapbase/style/moodle.css
@@ -7599,6 +7599,7 @@ body.path-question-type .mform fieldset.hidden {
 #groupeditform .groups select,
 #groupeditform .members select {
   min-width: 175px;
+  max-width: 90%;
 }
 /** Preferences page */
 .preferences-group ul {