--- CMakeLists.txt.orig	2021-01-17 06:47:55 UTC
+++ CMakeLists.txt
@@ -20,7 +20,9 @@ dune_project()
 dune_enable_all_packages()
 
 add_subdirectory(dune)
+if (FREEBSD_INSTALL_DOCS)
 add_subdirectory(doc)
+endif()
 add_subdirectory(cmake/modules)
 add_subdirectory(examples EXCLUDE_FROM_ALL)
 if (dune-python_FOUND)
