diff --git a/dist/css/bootstrap.css.map b/dist/css/bootstrap.css.map
index 8aacfe2aa..d30b02895 100644
Binary files a/dist/css/bootstrap.css.map and b/dist/css/bootstrap.css.map differ
diff --git a/less/buttons.less b/less/buttons.less
index 68664ea5c..b728f332c 100644
--- a/less/buttons.less
+++ b/less/buttons.less
@@ -18,32 +18,32 @@
   white-space: nowrap;
   .button-size(@padding-base-vertical; @padding-base-horizontal; @font-size-base; @line-height-base; @border-radius-base);
   .user-select(none);
-}
 
-.btn:focus {
-  .tab-focus();
-}
+  &:focus {
+    .tab-focus();
+  }
 
-.btn:hover,
-.btn:focus {
-  color: @btn-default-color;
-  text-decoration: none;
-}
+  &:hover,
+  &:focus {
+    color: @btn-default-color;
+    text-decoration: none;
+  }
 
-.btn:active,
-.btn.active {
-  outline: 0;
-  background-image: none;
-  .box-shadow(inset 0 3px 5px rgba(0,0,0,.125));
-}
+  &:active,
+  &.active {
+    outline: 0;
+    background-image: none;
+    .box-shadow(inset 0 3px 5px rgba(0,0,0,.125));
+  }
 
-.btn.disabled,
-.btn[disabled],
-fieldset[disabled] .btn {
-  cursor: not-allowed;
-  pointer-events: none; // Future-proof disabling of clicks
-  .opacity(.65);
-  .box-shadow(none);
+  &.disabled,
+  &[disabled],
+  fieldset[disabled] & {
+    cursor: not-allowed;
+    pointer-events: none; // Future-proof disabling of clicks
+    .opacity(.65);
+    .box-shadow(none);
+  }
 }