diff --git a/google-apis-core/lib/google/apis/core/storage_upload.rb b/google-apis-core/lib/google/apis/core/storage_upload.rb
index da31878d3a3..cd7e7823207 100644
--- a/google-apis-core/lib/google/apis/core/storage_upload.rb
+++ b/google-apis-core/lib/google/apis/core/storage_upload.rb
@@ -28,6 +28,7 @@ class StorageUploadCommand < ApiCommand
         CONTENT_LENGTH_HEADER = "Content-Length"
         CONTENT_TYPE_HEADER = "Content-Type"
         UPLOAD_CONTENT_TYPE_HEADER = "X-Upload-Content-Type"
+        UPLOAD_CONTENT_LENGTH_HEADER = "X-Upload-Content-Length"
         LOCATION_HEADER = "Location"
         CONTENT_RANGE_HEADER = "Content-Range"
         RESUMABLE = "resumable"
@@ -133,9 +134,9 @@ def initiate_resumable_upload(client)
           request_query = query.dup
           request_query['uploadType'] = RESUMABLE
 
-          request_header[CONTENT_LENGTH_HEADER] = upload_io.size.to_s
           request_header[CONTENT_TYPE_HEADER] = JSON_CONTENT_TYPE
           request_header[UPLOAD_CONTENT_TYPE_HEADER] = upload_content_type unless upload_content_type.nil?
+          request_header[UPLOAD_CONTENT_LENGTH_HEADER] = upload_io.size.to_s
 
           response = client.post(url.to_s, body, request_header) do |request|
             request.params.replace(request_query)
diff --git a/google-apis-core/spec/google/apis/core/storage_upload_spec.rb b/google-apis-core/spec/google/apis/core/storage_upload_spec.rb
index 7435f9cafe8..43bda9fcf68 100644
--- a/google-apis-core/spec/google/apis/core/storage_upload_spec.rb
+++ b/google-apis-core/spec/google/apis/core/storage_upload_spec.rb
@@ -51,6 +51,12 @@
       expect(a_request(:put, 'https://www.googleapis.com/zoo/animals')).to have_been_made
     end
 
+    it 'should send X-Upload-Content-Length in initiate request' do
+      command.execute(client)
+      expect(a_request(:post, 'https://www.googleapis.com/zoo/animals?uploadType=resumable')
+        .with { |req| req.headers.key?('X-Upload-Content-Length') }).to have_been_made
+    end
+
     it 'should generate a proper opencensus span' do
       OpenCensus::Trace.start_request_trace do |span_context|
         command.execute(client)