diff --git a/build/scss/_bootstrap-variables.scss b/build/scss/_bootstrap-variables.scss
index 270a6f848..b7473a9d6 100644
--- a/build/scss/_bootstrap-variables.scss
+++ b/build/scss/_bootstrap-variables.scss
@@ -760,6 +760,7 @@ $modal-title-line-height:           $line-height-base !default;
 $modal-content-bg:               $white !default;
 $modal-content-border-color:     rgba($black, .2) !default;
 $modal-content-border-width:     $border-width !default;
+$modal-content-border-radius:    $border-radius-lg !default;
 $modal-content-box-shadow-xs:    0 .25rem .5rem rgba($black, .5) !default;
 $modal-content-box-shadow-sm-up: 0 .5rem 1rem rgba($black, .5) !default;