diff --git a/BuildParams b/BuildParams
index 84d30f651bad54782baf50b8fb0f3dcb4e8c4900..5ee1bd11eaa97583815b1d6ec67220804a12567d 100755
--- a/BuildParams
+++ b/BuildParams
@@ -26,6 +26,9 @@ codeticket_since = 3.3.0-release
 Linux.gcc_version = /usr/bin/gcc-4.6
 Linux.cxx_version = /usr/bin/g++-4.6
 
+# Setup default sourceid so Windows can pick up the TeamCity override
+sourceid = ""
+
 ################################################################
 ####      Examples of how to set the viewer_channel         ####
 #
diff --git a/indra/newview/viewer_manifest.py b/indra/newview/viewer_manifest.py
index 206f81cdc20af0108b02232033eef4cd5f7c8654..827a8f44c36a82d1259a3bee65f2a2c813246aab 100755
--- a/indra/newview/viewer_manifest.py
+++ b/indra/newview/viewer_manifest.py
@@ -113,12 +113,14 @@ def construct(self):
                     # no sourceid, no settings_install.xml file
                     pass
                 else:
-                    # Single-entry subset of the LLSD content of settings.xml
-                    content = dict(sourceid=dict(Comment='Identify referring agency to Linden web servers',
-                                                 Persist=1,
-                                                 Type='String',
-                                                 Value=sourceid))
-                    self.put_in_file(llsd.format_pretty_xml(content), "settings_install.xml")
+                    if len(sourceid) > 0:
+                        print "Using sourceid: " + sourceid
+                        # Single-entry subset of the LLSD content of settings.xml
+                        content = dict(sourceid=dict(Comment='Identify referring agency to Linden web servers',
+                                                     Persist=1,
+                                                     Type='String',
+                                                     Value=sourceid))
+                        self.put_in_file(llsd.format_pretty_xml(content), "settings_install.xml")
 
                 self.end_prefix("app_settings")