diff --git a/docs/building-spark.md b/docs/building-spark.md
index 75c304a3ccecdafc0c852923e75b72093622a9a9..da7eeb8348378fd947dd5c4c25ff2b4e6554d4c3 100644
--- a/docs/building-spark.md
+++ b/docs/building-spark.md
@@ -215,6 +215,7 @@ For help in setting up IntelliJ IDEA or Eclipse for Spark development, and troub
 # Running Tests
 
 Tests are run by default via the [ScalaTest Maven plugin](http://www.scalatest.org/user_guide/using_the_scalatest_maven_plugin).
+Note that tests should not be run as root or an admin user.
 
 Some of the tests require Spark to be packaged first, so always run `mvn package` with `-DskipTests` the first time.  The following is an example of a correct (build, test) sequence: