diff --git a/lib/savon/builder.rb b/lib/savon/builder.rb
index 454c6f4f..13a17ef6 100644
--- a/lib/savon/builder.rb
+++ b/lib/savon/builder.rb
@@ -121,8 +121,9 @@ def namespaces
 
         if @wsdl&.document
           @wsdl.parser.namespaces.each do |identifier, path|
-            prefixed_identifier = identifier
-            prefixed_identifier = "xmlns:#{prefixed_identifier}" unless prefixed_identifier == 'xmlns'
+            next if identifier == 'xmlns' # Do not include xmlns namespace as this causes issues for some servers (https://github.com/savonrb/savon/issues/986)
+
+            prefixed_identifier = "xmlns:#{identifier}"
 
             next if namespaces.key?(prefixed_identifier)
 
diff --git a/spec/savon/softlayer_spec.rb b/spec/savon/softlayer_spec.rb
index a438c6da..b61b4284 100644
--- a/spec/savon/softlayer_spec.rb
+++ b/spec/savon/softlayer_spec.rb
@@ -21,7 +21,6 @@
       }
 
       expected_namespaces = {
-        'xmlns'           => "http://schemas.xmlsoap.org/wsdl/",
         'xmlns:xsd'       => "http://www.w3.org/2001/XMLSchema",
         'xmlns:xsi'       => "http://www.w3.org/2001/XMLSchema-instance",
         'xmlns:tns'       => "http://api.service.softlayer.com/soap/v3/",
@@ -34,7 +33,10 @@
       locals = Savon::LocalOptions.new(message)
       builder = Savon::Builder.new(:create_object, wsdl, globals, locals)
 
-      envelope = Nokogiri::XML(builder.to_s).xpath('./env:Envelope').first
+      parsed_doc = Nokogiri::XML(builder.to_s) do |config|
+        config.norecover.strict
+      end
+      envelope = parsed_doc.xpath('./env:Envelope').first
 
       expect(envelope.namespaces).to match(expected_namespaces)
     end