diff --git a/config_help.txt b/config_help.txt
index 9c9f8f7c622..e056620f71f 100644
--- a/config_help.txt
+++ b/config_help.txt
@@ -144,7 +144,7 @@ Build options:
   -unity-build ......... Enable Unity (Jumbo) build
   -unity-build-batch-size <int>
                          Maximum number of source files used by the unity build
-                         to create unity source files [8]
+                         to create unity source files [32]
 
   -warnings-are-errors . Treat warnings as errors [no; yes if -developer-build]