diff --git a/cmake/modules/Doxygen.cmake b/cmake/modules/Doxygen.cmake
index cf60eb3..a08f23b 100644
--- a/cmake/modules/Doxygen.cmake
+++ b/cmake/modules/Doxygen.cmake
@@ -3,7 +3,7 @@ if(NOT BASIC_PROJECT_CONFIG_DONE)
 endif()
 
 option(NO_DOXYGEN "whether creation of Doxygen targets is disabled (enabled by default)" OFF)
-if(NOT NO_DOXYGEN)
+if(NO_DOXYGEN)
     return()
 endif()