diff --git a/lib/api.rb b/lib/api.rb
index 8993c215102..f02c8d2e9c8 100644
--- a/lib/api.rb
+++ b/lib/api.rb
@@ -492,7 +492,8 @@ module Api
   # and adds context (e.g. /courses/:id/) if it is missing
   # exception: it leaves user-context file links alone
   def process_incoming_html_content(html)
-    Html::Content.process_incoming(html)
+    host = request.host_with_port if self.respond_to?(:request)
+    Html::Content.process_incoming(html, host: host)
   end
 
   def value_to_boolean(value)
diff --git a/lib/api/html/content.rb b/lib/api/html/content.rb
index 761ebfb7c99..a0909905088 100644
--- a/lib/api/html/content.rb
+++ b/lib/api/html/content.rb
@@ -21,9 +21,9 @@ require 'nokogiri'
 module Api
   module Html
     class Content
-      def self.process_incoming(html)
+      def self.process_incoming(html, host: nil)
         return html unless html.present?
-        content = self.new(html)
+        content = self.new(html, host: host)
         # shortcut html documents that definitely don't have anything we're interested in
         return html unless content.might_need_modification?
 
@@ -37,12 +37,12 @@ module Api
 
       attr_reader :html
 
-      def initialize(html_string, account = nil, include_mobile: false)
-        @account, @html, @include_mobile = account, html_string, include_mobile
+      def initialize(html_string, account = nil, include_mobile: false, host: nil)
+        @account, @html, @include_mobile, @host = account, html_string, include_mobile, host
       end
 
       def might_need_modification?
-        !!(html =~ %r{verifier=|\D/files|instructure_inline_media_comment})
+        !!(html =~ %r{verifier=|['"]/files|instructure_inline_media_comment})
       end
 
       # Take incoming html from a user or similar and modify it for safe storage and display
@@ -131,7 +131,7 @@ module Api
       end
 
       def corrected_link(link)
-        Html::Link.new(link).to_corrected_s
+        Html::Link.new(link, host: @host).to_corrected_s
       end
 
       def parsed_html
diff --git a/lib/api/html/link.rb b/lib/api/html/link.rb
index 5a6734c6976..610585ed015 100644
--- a/lib/api/html/link.rb
+++ b/lib/api/html/link.rb
@@ -22,13 +22,13 @@ module Api
   module Html
     class Link
       attr_reader :link
-      def initialize(link_string)
-        @link = link_string
+      def initialize(link_string, host: nil)
+        @link, @host = link_string, host
       end
 
       def to_corrected_s
         return link if is_not_actually_a_link? || should_skip_correction?
-        strip_verifier_params(scope_link_to_context(link))
+        strip_verifier_params(scope_link_to_context(strip_host(link)))
       end
 
       private
@@ -38,6 +38,17 @@ module Api
       LINK_REGEX = %r{/files/(\d+)/(?:download|preview)}
       VERIFIER_REGEX = %r{(\?)verifier=[^&]*&?|&verifier=[^&]*}
 
+      def strip_host(link)
+        return link if @host.nil?
+        uri = URI.parse(link)
+        if uri.host == @host
+          fragment = "##{uri.fragment}" if uri.fragment
+          "#{uri.request_uri}#{fragment}"
+        else
+          link
+        end
+      end
+
       def strip_verifier_params(local_link)
         if local_link.include?('verifier=')
           return local_link.gsub(VERIFIER_REGEX, '\1')
@@ -47,11 +58,9 @@ module Api
       end
 
       def scope_link_to_context(local_link)
-        uri = URI.parse(local_link)
-        if uri.path.start_with?('/files')
+        if local_link.start_with?('/files')
           if attachment && APPLICABLE_CONTEXT_TYPES.include?(attachment.context_type)
-            uri.path = "/#{attachment.context_type.underscore.pluralize}/#{attachment.context_id}#{uri.path}"
-            return uri.to_s
+            return "/#{attachment.context_type.underscore.pluralize}/#{attachment.context_id}" + local_link
           end
         end
 
diff --git a/spec/lib/api/html/content_spec.rb b/spec/lib/api/html/content_spec.rb
index 035a2a9879e..11943cec343 100644
--- a/spec/lib/api/html/content_spec.rb
+++ b/spec/lib/api/html/content_spec.rb
@@ -37,11 +37,6 @@ module Api
           expect(Content.new(string).might_need_modification?).to be(true)
         end
 
-        it 'is true for a link to files that include the host' do
-          string = "<body><a href='https://account.instructure.com/files'>link</a></body>"
-          expect(Content.new(string).might_need_modification?).to be(true)
-        end
-
         it 'is false for a link to files in a context' do
           string = "<body><a href='/courses/1/files'>link</a></body>"
           expect(Content.new(string).might_need_modification?).to be(false)
@@ -56,10 +51,11 @@ module Api
       describe "#modified_html" do
         it "scrubs links" do
           string = "<body><a href='http://somelink.com'>link</a></body>"
-          Html::Link.expects(:new).with("http://somelink.com").returns(
+          host = 'some-host'
+          Html::Link.expects(:new).with("http://somelink.com", host: host).returns(
             stub(to_corrected_s: "http://otherlink.com")
           )
-          html = Content.new(string).modified_html
+          html = Content.new(string, host: host).modified_html
           expect(html).to match(/otherlink.com/)
         end
 
diff --git a/spec/lib/api/html/link_spec.rb b/spec/lib/api/html/link_spec.rb
index e69577b0be4..2b628b775b6 100644
--- a/spec/lib/api/html/link_spec.rb
+++ b/spec/lib/api/html/link_spec.rb
@@ -49,11 +49,28 @@ module Api
           expect(Link.new(raw_link).to_corrected_s).to eq "/courses/1/files/1/download?"
         end
 
-        it 'scopes to the context even if url includes the host' do
+        it 'scopes to the context if url includes the host' do
           course_attachment = stub(context_type: "Course", context_id: 1)
           Attachment.stubs(:where).with(id: "1").returns(stub(first: course_attachment))
-          raw_link = "https://account.instructure.com/files/1/download?verifier=123"
-          expect(Link.new(raw_link).to_corrected_s).to eq "https://account.instructure.com/courses/1/files/1/download?"
+          host = 'account.instructure.com'
+          raw_link = "https://#{host}/files/1/download?verifier=123"
+          expect(Link.new(raw_link, host: host).to_corrected_s).to eq "/courses/1/files/1/download?"
+        end
+
+        it 'strips the current host from absolute urls' do
+          course_attachment = stub(context_type: "Course", context_id: 1)
+          Attachment.stubs(:where).with(id: "1").returns(stub(first: course_attachment))
+          host = 'account.instructure.com'
+          raw_link = "https://#{host}/courses/1/files/1/download?"
+          expect(Link.new(raw_link, host: host).to_corrected_s).to eq "/courses/1/files/1/download?"
+        end
+
+        it 'does not scope to the context if url includes a differnt host' do
+          course_attachment = stub(context_type: "Course", context_id: 1)
+          Attachment.stubs(:where).with(id: "1").returns(stub(first: course_attachment))
+          host = 'account.instructure.com'
+          raw_link = "https://#{host}/files/1/download"
+          expect(Link.new(raw_link, host: 'other-host').to_corrected_s).to eq raw_link
         end
       end
     end
diff --git a/spec/lib/api_spec.rb b/spec/lib/api_spec.rb
index f3e5d975f98..c6b07308f1a 100644
--- a/spec/lib/api_spec.rb
+++ b/spec/lib/api_spec.rb
@@ -697,6 +697,9 @@ describe Api do
   context ".process_incoming_html_content" do
     class T
       extend Api
+      def self.request
+        OpenStruct.new({host_with_port: 'some-host'})
+      end
     end
 
     it "should add context to files and remove verifier parameters" do
@@ -725,6 +728,11 @@ describe Api do
         <a href="/courses/#{@course.id}/files/#{@attachment.id}/notdownload?b=2&amp;verifier=shouldstay&amp;c=2">but not here</a>
       </div>}
     end
+
+    it 'passes host to Content.process_incoming' do
+      Api::Html::Content.expects(:process_incoming).with(anything, host: 'some-host')
+      T.process_incoming_html_content('<div/>')
+    end
   end
 
   context ".paginate" do