diff --git a/theme/boost/scss/moodle/core.scss b/theme/boost/scss/moodle/core.scss
index e21ca4bb2e0..1c3ee3fcfeb 100644
--- a/theme/boost/scss/moodle/core.scss
+++ b/theme/boost/scss/moodle/core.scss
@@ -1974,6 +1974,10 @@ a.disabled {
     color: $text-muted;
 }
 
+a.btn.disabled {
+    opacity: 1;
+}
+
 body.lockscroll {
     height: 100%;
     overflow: hidden;
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index 7790c0099e8..36dfa1fe71c 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -24971,6 +24971,10 @@ a.disabled {
   color: #6a737b;
 }
 
+a.btn.disabled {
+  opacity: 1;
+}
+
 body.lockscroll {
   height: 100%;
   overflow: hidden;
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index b7ff0a8d67f..41a60b43906 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -24971,6 +24971,10 @@ a.disabled {
   color: #6a737b;
 }
 
+a.btn.disabled {
+  opacity: 1;
+}
+
 body.lockscroll {
   height: 100%;
   overflow: hidden;