diff --git a/frameworks/compass/stylesheets/compass/css3/_transition.scss b/frameworks/compass/stylesheets/compass/css3/_transition.scss
index d0c74a05..60487bcc 100644
--- a/frameworks/compass/stylesheets/compass/css3/_transition.scss
+++ b/frameworks/compass/stylesheets/compass/css3/_transition.scss
@@ -40,7 +40,8 @@ $default-transition-delay: false !default;
 // * these durations will affect the properties in the same list position
 
 @mixin transition-duration($duration: $default-transition-duration) {
-  @include experimental(transition-duration, unquote($duration),
+  @if type-of($duration) == string { $duration: unquote($duration); }
+  @include experimental(transition-duration, $duration,
     -moz, -webkit, -o, not -ms, not -khtml, official
   );
 }
@@ -63,7 +64,8 @@ $default-transition-delay: false !default;
 // * these delays will effect the properties in the same list position
 
 @mixin transition-delay($delay: $default-transition-delay) {
-  @include experimental(transition-delay, unquote($delay),
+  @if type-of($delay) == string { $delay: unquote($delay); }
+  @include experimental(transition-delay, $delay,
     -moz, -webkit, -o, not -ms, not -khtml, official
   );
 }