diff --git a/Source/cmIncludeDirectoryCommand.h b/Source/cmIncludeDirectoryCommand.h
index d00f84345..3b35d55de 100644
--- a/Source/cmIncludeDirectoryCommand.h
+++ b/Source/cmIncludeDirectoryCommand.h
@@ -61,7 +61,7 @@ public:
       "Add the given directories to those searched by the compiler for "
       "include files. By default the directories are appended onto "
       "the current list of directories. This default behavior can be "
-      "changed by setting CMAKE_include_directories_BEFORE to ON. "
+      "changed by setting CMAKE_INCLUDE_DIRECTORIES_BEFORE to ON. "
       "By using BEFORE or AFTER you can select between appending and "
       "prepending, independent from the default. "
       "If the SYSTEM option is given the compiler will be told that the "