diff --git a/deploy/lib/ml_rest.rb b/deploy/lib/ml_rest.rb
index 8f1c0a5a..3891531e 100644
--- a/deploy/lib/ml_rest.rb
+++ b/deploy/lib/ml_rest.rb
@@ -44,13 +44,19 @@ def install_properties(path)
           file = open(d, "rb")
           contents = file.read
 
-          # @logger.debug "methods: #{methods}"
-          url = "http://#{@hostname}:#{@port}/v1/config/properties"
-
-          @logger.debug "url: #{url}"
-          r = go url, "put", headers, nil, contents, @auth_method
-          if (r.code.to_i < 200 && r.code.to_i > 206)
-            @logger.error("code: #{r.code.to_i} body:#{r.body}")
+          if contents.match('<properties')
+            # Properties is in the correct format
+            # @logger.debug "methods: #{methods}"
+            url = "http://#{@hostname}:#{@port}/v1/config/properties"
+
+            @logger.debug "url: #{url}"
+            r = go url, "put", headers, nil, contents, @auth_method
+            if (r.code.to_i < 200 && r.code.to_i > 206)
+              @logger.error("code: #{r.code.to_i} body:#{r.body}")
+            end
+          else
+            # Properties file needs to be updated
+            raise ExitException.new "#{d} is in an old format; changes to this file won't take effect. See https://github.com/marklogic/roxy/wiki/REST-properties-format-change"
           end
         end
       else