diff --git a/scss/_button-group.scss b/scss/_button-group.scss
index d85c637679f2fb2d4bf5909ca86a9ad412b65a11..68ab172f04e4f3a54e1ae35055dc51fe29e67b73 100644
--- a/scss/_button-group.scss
+++ b/scss/_button-group.scss
@@ -94,8 +94,14 @@
 //
 // Remix the default button sizing classes into new ones for easier manipulation.
 
-.btn-group-sm > .btn { @extend .btn-sm; }
-.btn-group-lg > .btn { @extend .btn-lg; }
+.btn-group-sm > .btn,
+.btn-group-sm .btn-group > .btn {
+  @extend .btn-sm;
+}
+.btn-group-lg > .btn,
+.btn-group-lg .btn-group > .btn {
+  @extend .btn-lg;
+}
 
 
 //