diff --git a/README.md b/README.md
index 44ebdd014217f9983c0cbb9bc5a2d4ff60adc5b1..d8545990ee2caca05b2e9bb78e35b9748f67b9b9 100644
--- a/README.md
+++ b/README.md
@@ -580,7 +580,7 @@ Data Science Toolkit provides an API whose reponse format is like Google's but w
 * **API key**: requires auth_id and auth_token (set `Geocoder.configure(:api_key => [id, token])`)
 * **Quota**: 10,000 free, 250/month then purchase at sliding scale.
 * **Region**: US
-* **SSL support**: yes
+* **SSL support**: yes (required)
 * **Languages**: en
 * **Documentation**: http://smartystreets.com/kb/liveaddress-api/rest-endpoint
 * **Terms of Service**: http://smartystreets.com/legal/terms-of-service
diff --git a/lib/geocoder/lookups/smarty_streets.rb b/lib/geocoder/lookups/smarty_streets.rb
index db48738fd94d1efcbdee44e9c6a6342f085b0c55..2aebf07a1c71b6260af98846a39c24604883f783 100644
--- a/lib/geocoder/lookups/smarty_streets.rb
+++ b/lib/geocoder/lookups/smarty_streets.rb
@@ -18,6 +18,10 @@ module Geocoder::Lookup
 
     private # ---------------------------------------------------------------
 
+    def protocol
+      "https" # required by API as of 26 March 2015
+    end
+
     def zipcode_only?(query)
       !query.text.is_a?(Array) and query.to_s.strip =~ /\A\d{5}(-\d{4})?\Z/
     end
diff --git a/test/unit/lookups/smarty_streets_test.rb b/test/unit/lookups/smarty_streets_test.rb
index b9c7f0c7d90de197cbd8ae9682eeb313909d4fd2..7befd0446b58d2dad04ff01ec0002308ad29adb9 100644
--- a/test/unit/lookups/smarty_streets_test.rb
+++ b/test/unit/lookups/smarty_streets_test.rb
@@ -11,7 +11,7 @@ class SmartyStreetsTest < GeocoderTestCase
   def test_url_contains_api_key
     Geocoder.configure(:smarty_streets => {:api_key => 'blah'})
     query = Geocoder::Query.new("Bluffton, SC")
-    assert_equal "http://api.smartystreets.com/street-address?auth-token=blah&street=Bluffton%2C+SC", query.url
+    assert_equal "https://api.smartystreets.com/street-address?auth-token=blah&street=Bluffton%2C+SC", query.url
   end
 
   def test_query_for_address_geocode