diff --git a/scss/_alert.scss b/scss/_alert.scss
index b9f6c60dad2e069bccd60d0dcd5849c345c693b3..b3dcf032108684915429bf469264b24aece6fa57 100644
--- a/scss/_alert.scss
+++ b/scss/_alert.scss
@@ -35,7 +35,7 @@
 // Expand the right padding and account for the close button's positioning.
 
 .alert-dismissible {
-  padding-right: ($alert-padding + 20);
+  padding-right: ($alert-padding + 20px);
 
   // Adjust close link position
   .close {
diff --git a/scss/_variables.scss b/scss/_variables.scss
index cb478d76a15ec031f51a76d9c8d8fa19beadc27d..4042dc8357ce72b0d4841e177d1ba74084b6a2da 100644
--- a/scss/_variables.scss
+++ b/scss/_variables.scss
@@ -506,7 +506,7 @@ $popover-title-bg:                    darken($popover-bg, 3%) !default;
 $popover-arrow-width:                 10px !default;
 $popover-arrow-color:                 $popover-bg !default;
 
-$popover-arrow-outer-width:           ($popover-arrow-width + 1) !default;
+$popover-arrow-outer-width:           ($popover-arrow-width + 1px) !default;
 $popover-arrow-outer-color:           fade-in($popover-border-color, 0.05) !default;