diff --git a/scss/_input-group.scss b/scss/_input-group.scss
index 7ebc313d37b9..707207b0238e 100644
--- a/scss/_input-group.scss
+++ b/scss/_input-group.scss
@@ -12,6 +12,7 @@
   width: 100%;
 
   > .form-control,
+  > .form-control-plaintext,
   > .custom-select,
   > .custom-file {
     position: relative; // For focus state's z-index