diff --git a/lib/tracking_number/base.rb b/lib/tracking_number/base.rb
index 4a905b3..f1eaa09 100644
--- a/lib/tracking_number/base.rb
+++ b/lib/tracking_number/base.rb
@@ -24,7 +24,7 @@ def self.scan(body)
       # matches with match groups within the match data
       matches = []
 
-      body.scan(const_get(:SEARCH_PATTERN)) do
+      body.upcase.scan(const_get(:SEARCH_PATTERN)) do
         # get the match data instead, which is needed with these types of regexes
         matches << $~
       end
diff --git a/test/tracking_number_test.rb b/test/tracking_number_test.rb
index 3baccad..55e2d1e 100644
--- a/test/tracking_number_test.rb
+++ b/test/tracking_number_test.rb
@@ -40,6 +40,12 @@ class TrackingNumberTest < Minitest::Test
       assert_equal 1, s.size
       assert_equal "1Z879E930346834440", s.first.tracking_number
     end
+
+    should "return tracking numbers entered as lowercase" do
+      s = TrackingNumber.search("hello 1z879E930346834440 bye")
+      assert_equal 1, s.size
+      assert_equal "1Z879E930346834440", s.first.tracking_number
+    end
   end
 
   context "tracking number additional data for ups" do
@@ -201,7 +207,7 @@ class TrackingNumberTest < Minitest::Test
   context "searching numbers that have partners" do
     partnership_number = "420 11213 92 6129098349792366623 8"
     single_number = "92001903060085300042901077"
-  
+
     search_string = ["number that matches two services", partnership_number, " number that matches only one: ", single_number, "let's see if that does it"].join(' ')
 
     should "match only carriers by default" do