diff --git a/lib/microformats2/format.rb b/lib/microformats2/format.rb
index 7b642dc..74ba975 100644
--- a/lib/microformats2/format.rb
+++ b/lib/microformats2/format.rb
@@ -41,7 +41,7 @@ module Microformats2
     def parse_implied_properties
       ip = []
       ip << ImpliedProperty::Name.new(@element).parse unless property_present?(:name)
-      ip << ImpliedProperty::Url.new(@element).parse unless property_present?(:url)
+      ip << ImpliedProperty::Url.new(@element, @base).parse unless property_present?(:url)
       ip << ImpliedProperty::Photo.new(@element).parse unless property_present?(:photo)
       ip.compact.each do |property|
         save_property_name(property.method_name)
diff --git a/lib/microformats2/implied_property/foundation.rb b/lib/microformats2/implied_property/foundation.rb
index 57bf199..fcd8fa4 100644
--- a/lib/microformats2/implied_property/foundation.rb
+++ b/lib/microformats2/implied_property/foundation.rb
@@ -2,8 +2,9 @@ module Microformats2
   module ImpliedProperty
     class Foundation
 
-      def initialize(element)
+      def initialize(element, base=nil)
         @element = element
+        @base = base
       end
 
       def parse
diff --git a/lib/microformats2/implied_property/url.rb b/lib/microformats2/implied_property/url.rb
index 1fb3af0..54ae407 100644
--- a/lib/microformats2/implied_property/url.rb
+++ b/lib/microformats2/implied_property/url.rb
@@ -6,6 +6,22 @@ module Microformats2
         "url"
       end
 
+      def to_s
+        @to_s = absolutize(super.to_s) if super.to_s != ""
+      end
+
+      # TODO: make dry, repeated in Collection
+      def absolutize(href)
+        uri = URI.parse(href)
+
+        if @base && !uri.absolute?
+          uri = URI.join(@base, href)
+        end
+
+        uri.normalize!
+        uri.to_s
+      end
+
       protected
 
       def name_map
diff --git a/spec/lib/microformats2/implied_property/url_spec.rb b/spec/lib/microformats2/implied_property/url_spec.rb
index 3c736f0..9a99b80 100644
--- a/spec/lib/microformats2/implied_property/url_spec.rb
+++ b/spec/lib/microformats2/implied_property/url_spec.rb
@@ -15,6 +15,33 @@ describe Microformats2::ImpliedProperty::Url do
         end
       end
     end
+
+    describe "url-relative.html" do
+      html = "spec/support/lib/microformats2/implied_property/url-relative.html"
+      collection = Microformats2.parse(html)
+      it "should have 2 microformats" do
+        collection.all.length.should == 2
+      end
+      collection.all.each_with_index do |format, index|
+        it "implies url to be 'http://example.org/' in case #{index+1}" do
+          format.url.to_s.should == "http://example.org/"
+        end
+      end
+    end
+
+    describe "url-unnormalized.html" do
+      html = "spec/support/lib/microformats2/implied_property/url-unnormalized.html"
+      collection = Microformats2.parse(html)
+      it "should have 2 microformats" do
+        collection.all.length.should == 2
+      end
+      collection.all.each_with_index do |format, index|
+        it "implies url to be 'http://github.com/' in case #{index+1}" do
+          format.url.to_s.should == "http://github.com/"
+        end
+      end
+    end
+
     describe "url-fail.html" do
       html = "spec/support/lib/microformats2/implied_property/url-fail.html"
       collection = Microformats2.parse(html)
@@ -22,8 +49,8 @@ describe Microformats2::ImpliedProperty::Url do
         collection.all.length.should == 2
       end
       collection.all.each_with_index do |format, index|
-        it "implies url to be '' in case #{index+1}" do
-          expect {format.url.to_s.should == ""}.to raise_error(NoMethodError)
+        it "does not imply url in case #{index+1}" do
+          expect {format.url}.to raise_error(NoMethodError)
         end
       end
     end
diff --git a/spec/support/lib/microformats2/implied_property/url-relative.html b/spec/support/lib/microformats2/implied_property/url-relative.html
new file mode 100644
index 0000000..a382200
--- /dev/null
+++ b/spec/support/lib/microformats2/implied_property/url-relative.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html>
+<body>
+<base href="http://example.org/">
+
+<a class="h-card" href="/" />
+
+<div class="h-card">
+  <a href="/" />
+</div>
+
+</body>
+</html>
diff --git a/spec/support/lib/microformats2/implied_property/url-unnormalized.html b/spec/support/lib/microformats2/implied_property/url-unnormalized.html
new file mode 100644
index 0000000..641af02
--- /dev/null
+++ b/spec/support/lib/microformats2/implied_property/url-unnormalized.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<body>
+
+<a class="h-card" href="http://github.com" />
+
+<div class="h-card">
+  <a href="http://github.com" />
+</div>
+
+</body>
+</html>