diff --git a/examples/css3/src/main.scss b/examples/css3/src/main.scss
index 31acb2cd..5396a0c1 100644
--- a/examples/css3/src/main.scss
+++ b/examples/css3/src/main.scss
@@ -32,6 +32,10 @@ h1 {
     margin: 0.5em 0 1em;
     text-align: center; } }
 
+.inset {
+  @include box-shadow(darken($border_color, 40), 5px, 5px, 2px, 3px, inset);
+}
+
 .gutter {
   display: block;
   float: left;
diff --git a/frameworks/compass/stylesheets/compass/css3/_box-shadow.scss b/frameworks/compass/stylesheets/compass/css3/_box-shadow.scss
index 76b78b91..6d7dcd29 100644
--- a/frameworks/compass/stylesheets/compass/css3/_box-shadow.scss
+++ b/frameworks/compass/stylesheets/compass/css3/_box-shadow.scss
@@ -36,7 +36,10 @@ $default-box-shadow-inset : false !default;
 ) {
   $full   : $color $hoff $voff $blur $spread;
   @if $inset {
-    $full: $full $inset;
+    @if not ($inset == true or $inset == inset) {
+      @warn "$inset expected to be true or the inset keyword. Got #{$inset} instead. The box shadow will be inset."
+    }
+    $full: $full inset;
   }
   @if $color == none {
     @include experimental(box-shadow, none,