diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -3,6 +3,8 @@
 SET(abs_top_srcdir ${PROJECT_SOURCE_DIR})
 SET(abs_top_builddir ${PROJECT_BINARY_DIR})
 
+SET(LEMON_DOC_SOURCE_BROWSER "NO" CACHE STRING "Include source into the doc (YES/NO).")
+
 CONFIGURE_FILE(
   ${PROJECT_SOURCE_DIR}/doc/Doxyfile.in
   ${PROJECT_BINARY_DIR}/doc/Doxyfile