diff --git a/lib/restclient.rb b/lib/restclient.rb
index 642f8ad..fbcc97d 100644
--- a/lib/restclient.rb
+++ b/lib/restclient.rb
@@ -94,7 +94,7 @@ module RestClient
   # A global proxy URL to use for all requests. This can be overridden on a
   # per-request basis by passing `:proxy` to RestClient::Request.
   def self.proxy
-    @proxy
+    @proxy ||= nil
   end
   def self.proxy=(value)
     @proxy = value
diff --git a/lib/restclient/abstract_response.rb b/lib/restclient/abstract_response.rb
index cde1bd6..680330c 100644
--- a/lib/restclient/abstract_response.rb
+++ b/lib/restclient/abstract_response.rb
@@ -64,7 +64,7 @@ module RestClient
     # @return [HTTP::CookieJar]
     #
     def cookie_jar
-      return @cookie_jar if @cookie_jar
+      return @cookie_jar if defined?(@cookie_jar) && @cookie_jar
 
       jar = @request.cookie_jar.dup
       headers.fetch(:set_cookie, []).each do |cookie|
diff --git a/lib/restclient/payload.rb b/lib/restclient/payload.rb
index fc08d8f..56563fa 100644
--- a/lib/restclient/payload.rb
+++ b/lib/restclient/payload.rb
@@ -174,7 +174,7 @@ module RestClient
       end
 
       def boundary
-        return @boundary if @boundary
+        return @boundary if defined?(@boundary) && @boundary
 
         # Use the same algorithm used by WebKit: generate 16 random
         # alphanumeric characters, replacing `+` `/` with `A` `B` (included in
diff --git a/lib/restclient/request.rb b/lib/restclient/request.rb
index d82a639..d0c7bd4 100644
--- a/lib/restclient/request.rb
+++ b/lib/restclient/request.rb
@@ -124,6 +124,8 @@ module RestClient
       else
         raise ArgumentError, "must pass :url"
       end
+
+      @user = @password = nil
       parse_url_with_auth!(url)
 
       # process cookie arguments found in headers or args
@@ -815,7 +817,7 @@ module RestClient
         # Kudos to _why!
         @tf = Tempfile.new('rest-client.')
         @tf.binmode
-        size, total = 0, http_response.header['Content-Length'].to_i
+        size, total = 0, http_response['Content-Length'].to_i
         http_response.read_body do |chunk|
           @tf.write chunk
           size += chunk.size
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index c43a240..bca8e28 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -13,6 +13,10 @@ RSpec.configure do |config|
   #     --seed 1234
   config.order = 'random'
 
+  # always run with ruby warnings enabled
+  # TODO: figure out why this is so obscenely noisy (rspec bug?)
+  # config.warnings = true
+
   # add helpers
   config.include Helpers, :include_helpers
 
@@ -20,3 +24,6 @@ RSpec.configure do |config|
     mocks.yield_receiver_to_any_instance_implementation_blocks = true
   end
 end
+
+# always run with ruby warnings enabled (see above)
+$VERBOSE = true