diff --git a/tools/buildman/README b/tools/buildman/README
index 8e7a68c..68456ce 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -699,6 +699,17 @@
 enabled automatically). Use -e to see errors/warnings as well.
 
 
+Building Ranges
+===============
+
+You can build a range of commits by specifying a range instead of a branch
+when using the -b flag. For example:
+
+    upstream/master..us-buildman
+
+will build commits in us-buildman that are not in upstream/master.
+
+
 Other options
 =============