diff --git a/doc/bitbake-user-manual/bitbake-user-manual-execution.rst b/doc/bitbake-user-manual/bitbake-user-manual-execution.rst
index d407f59c0..b624fe8f6 100644
--- a/doc/bitbake-user-manual/bitbake-user-manual-execution.rst
+++ b/doc/bitbake-user-manual/bitbake-user-manual-execution.rst
@@ -241,7 +241,7 @@ upstream repository, but with custom modifications that one does not
 want upstream. Here is an example::

   BBFILES = "/stuff/openembedded/*/*.bb /stuff/openembedded.modified/*/*.bb"
-  BBFILE_COLLECTIONS = "upstream local"
+  BBFILE_COLLECTIONS += "upstream local"
   BBFILE_PATTERN_upstream = "^/stuff/openembedded/"
   BBFILE_PATTERN_local = "^/stuff/openembedded.modified/"
   BBFILE_PRIORITY_upstream = "5"