--- CMakeLists.txt.orig	2020-03-15 19:45:36 UTC
+++ CMakeLists.txt
@@ -9,7 +9,9 @@ include(DuneMacros)
 dune_project()
 
 add_subdirectory(cmake/modules)
+if (FREEBSD_INSTALL_DOCS)
 add_subdirectory(doc)
+endif()
 add_subdirectory(dune)
 
 if(dune-python_FOUND)