diff --git a/doc/build-doc.py b/doc/build-doc.py
index 9a3846bb..517c6f28 100644
--- a/doc/build-doc.py
+++ b/doc/build-doc.py
@@ -368,6 +368,8 @@ def print_usage(appname, output):
         build_man = True
     if o == '--pdf':
         build_pdf = True
+    if o == '--all':
+        allowContrib = True
 
 if not args:
     print("error: build directory not specified\n", file=sys.stderr)