diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2300cb34..0e294eb5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,4 @@
-# Generated by `boostdep --cmake graph`
-# Copyright 2020 Peter Dimov
+# Copyright 2020, 2021 Peter Dimov
 # Distributed under the Boost Software License, Version 1.0.
 # https://www.boost.org/LICENSE_1_0.txt
 
@@ -64,7 +63,8 @@ target_link_libraries(boost_graph
 
 target_compile_definitions(boost_graph
   PUBLIC BOOST_GRAPH_NO_LIB
-  PRIVATE BOOST_GRAPH_SOURCE
+  # Source files already define BOOST_GRAPH_SOURCE
+  # PRIVATE BOOST_GRAPH_SOURCE
 )
 
 if(BUILD_SHARED_LIBS)
@@ -78,4 +78,3 @@ if(BUILD_TESTING AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/test/CMakeLists.txt")
   add_subdirectory(test)
 
 endif()
-