diff --git a/CHANGELOG.md b/CHANGELOG.md
index 572ebbc..eec398b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## Unreleased ##
+
+* Fixes bug where 0 and 0px are not reconciled as redundancies
+
 ## 1.1.0 - 4/12/2013 ##
 
 * Fixes bug where CLI --no-color wasn't respected
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
index f877ddf..9564593 100644
--- a/CONTRIBUTORS.md
+++ b/CONTRIBUTORS.md
@@ -2,3 +2,4 @@
 * Carson McDonald @carsonmcdonald
 * Martin Kuckert @MKuckert
 * Ivan Lazarevic @kopipejst
+* Matt DuVall @mduvall
diff --git a/lib/csscss/parser/common.rb b/lib/csscss/parser/common.rb
index 4a3d965..fe960c3 100644
--- a/lib/csscss/parser/common.rb
+++ b/lib/csscss/parser/common.rb
@@ -3,19 +3,21 @@ module Parser
     module Common
       include Parslet
 
-      UNITS = %w(px em ex in cm mm pt pc)
+      UNITS = %w(px em ex in cm mm pt pc %)
 
-      rule(:space)      { match['\s'].repeat(1) }
-      rule(:space?)     { space.maybe }
-      rule(:number)     { match["0-9"] }
-      rule(:numbers)    { number.repeat(1) }
-      rule(:decimal)    { numbers >> str(".").maybe >> numbers.maybe }
-      rule(:percent)    { decimal >> stri("%") >> space? }
-      rule(:length)     { decimal >> stri_list(UNITS) >> space?  }
-      rule(:identifier) { match["a-zA-Z"].repeat(1) }
-      rule(:inherit)    { stri("inherit") }
-      rule(:eof)        { any.absent? }
-      rule(:nada)       { any.repeat.as(:nada) }
+      rule(:space)                { match['\s'].repeat(1) }
+      rule(:space?)               { space.maybe }
+      rule(:number)               { match["0-9"] }
+      rule(:numbers)              { number.repeat(1) }
+      rule(:decimal)              { numbers >> str(".").maybe >> numbers.maybe }
+      rule(:percent)              { decimal >> stri("%") >> space? }
+      rule(:non_zero_length)      { decimal >> stri_list(UNITS) >> space?  }
+      rule(:zero_length)          { match["0"] }
+      rule(:length)               { zero_length | non_zero_length }
+      rule(:identifier)           { match["a-zA-Z"].repeat(1) }
+      rule(:inherit)              { stri("inherit") }
+      rule(:eof)                  { any.absent? }
+      rule(:nada)                 { any.repeat.as(:nada) }
 
       rule(:http) {
         (match['a-zA-Z0-9.:/\-'] | str('\(') | str('\)')).repeat >> space?
diff --git a/lib/csscss/redundancy_analyzer.rb b/lib/csscss/redundancy_analyzer.rb
index fd0773c..be9de91 100644
--- a/lib/csscss/redundancy_analyzer.rb
+++ b/lib/csscss/redundancy_analyzer.rb
@@ -65,7 +65,6 @@ def redundancies(opts = {})
         end
       end
 
-
       # trims any derivative declarations alongside shorthand
       inverted_matches.each do |selectors, declarations|
         redundant_derivatives = declarations.select do |dec|
diff --git a/lib/csscss/types.rb b/lib/csscss/types.rb
index 0cbcd74..0d00367 100644
--- a/lib/csscss/types.rb
+++ b/lib/csscss/types.rb
@@ -36,8 +36,17 @@ def ==(other)
       end
     end
 
+    def normalized_value
+      zero_units = Csscss::Parser::Common::UNITS.map {|u| '0' + u}
+      if zero_units.include? value
+        "0"
+      else
+        value
+      end
+    end
+
     def hash
-      [property, value].hash
+      [property, normalized_value].hash
     end
 
     def eql?(other)
diff --git a/test/csscss/parser/common_test.rb b/test/csscss/parser/common_test.rb
index 75fbde6..06486b8 100644
--- a/test/csscss/parser/common_test.rb
+++ b/test/csscss/parser/common_test.rb
@@ -106,6 +106,7 @@ class CommonTest
         @parser.length.must_parse "123px"
         @parser.length.must_parse "123EM"
         @parser.length.must_parse "1.23Pt"
+        @parser.length.must_parse "0"
       end
     end
 
diff --git a/test/csscss/redundancy_analyzer_test.rb b/test/csscss/redundancy_analyzer_test.rb
index 7de8b88..8f72e25 100644
--- a/test/csscss/redundancy_analyzer_test.rb
+++ b/test/csscss/redundancy_analyzer_test.rb
@@ -275,6 +275,18 @@ module Csscss
       })
     end
 
+    it "matches 0 and 0px" do
+      css = %$
+        .bar { padding: 0; }
+        .foo { padding: 0px; }
+      $
+
+      RedundancyAnalyzer.new(css).redundancies.must_equal({
+        [sel(".bar"), sel(".foo")] => [dec("padding", "0")]
+      })
+    end
+
+
     # TODO: someday
     # it "reports duplication within the same selector" do
     #   css = %$
diff --git a/test/csscss/types_test.rb b/test/csscss/types_test.rb
index de80520..a443bb8 100644
--- a/test/csscss/types_test.rb
+++ b/test/csscss/types_test.rb
@@ -69,5 +69,17 @@ module Csscss
       h[dec2].must_equal true
       h[dec3].must_equal true
     end
+
+    it "stores values of normalized zeros for length units" do
+      dec1 = Declaration.new("padding", "0px")
+
+      dec1.normalized_value.must_equal "0"
+    end
+
+    it "stores values of non-normalized numbers for length units" do
+      dec1 = Declaration.new("padding", "1px")
+
+      dec1.normalized_value.must_equal "1px"
+    end
   end
 end