diff --git a/Gemfile.lock b/Gemfile.lock
index 46f8736d..93a1392e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,7 +7,7 @@ GIT
 PATH
   remote: .
   specs:
-    compass (0.11.beta.4.4d7dc7a)
+    compass (0.11.beta.4.c3f0053)
       chunky_png (~> 1.1.0)
       sass (>= 3.1.0.alpha.249)
 
diff --git a/lib/compass/sass_extensions/sprites/image.rb b/lib/compass/sass_extensions/sprites/image.rb
index aff1931a..3a3e57cf 100644
--- a/lib/compass/sass_extensions/sprites/image.rb
+++ b/lib/compass/sass_extensions/sprites/image.rb
@@ -5,7 +5,7 @@ module Compass
         ACTIVE = %r{[_-]active$}
         TARGET = %r{[_-]target$}
         HOVER = %r{[_-]hover$}
-        PARENT = %r{(.+)_(.+)$}
+        PARENT = %r{(.+)[-_](.+)$}
         
         attr_reader :relative_file, :options, :base
         attr_accessor :top, :left