diff --git a/spec/app/text-mate-theme-spec.coffee b/spec/app/text-mate-theme-spec.coffee
index 43c176174..953118089 100644
--- a/spec/app/text-mate-theme-spec.coffee
+++ b/spec/app/text-mate-theme-spec.coffee
@@ -46,7 +46,7 @@ describe "TextMateTheme", ->
       expect(rulesets[2]).toEqual
         selector: '.editor.focused .selection'
         properties:
-          'background-color': "rgba(221, 240, 255, 51)"
+          'background-color': "rgba(221, 240, 255, .2)"
 
     it "returns an array of objects representing the theme's scope selectors", ->
       expect(rulesets[11]).toEqual
@@ -62,4 +62,4 @@ describe "TextMateTheme", ->
         selector: ".invalid-illegal"
         properties:
           'color': "#F8F8F8"
-          'background-color': 'rgba(86, 45, 86, 191)'
+          'background-color': 'rgba(86, 45, 86, parseInt(textmateColor[7..8], 16))'
diff --git a/src/app/text-mate-theme.coffee b/src/app/text-mate-theme.coffee
index c7c3bd41b..03a20ce93 100644
--- a/src/app/text-mate-theme.coffee
+++ b/src/app/text-mate-theme.coffee
@@ -105,4 +105,4 @@ class TextMateTheme
       g = parseInt(textmateColor[3..4], 16)
       b = parseInt(textmateColor[5..6], 16)
       a = parseInt(textmateColor[7..8], 16)
-      "rgba(#{r}, #{g}, #{b}, #{a})"
+      "rgba(#{r}, #{g}, #{b}, #{a / 255.0})"