diff --git a/CMakeOptions.txt b/CMakeOptions.txt
index 55375116e..5eff4c311 100644
--- a/CMakeOptions.txt
+++ b/CMakeOptions.txt
@@ -29,11 +29,15 @@ option(GLFW_BUILD_WAYLAND "Build the bundled GLFW with Wayland support" OFF)
 option(GLFW_BUILD_X11 "Build the bundled GLFW with X11 support" ON)
 
 option(INCLUDE_EVERYTHING "Include everything disabled by default (for CI usage)" OFF)
-set(OFF ${INCLUDE_EVERYTHING} CACHE INTERNAL "Replace any OFF by default with \${OFF} to have it covered by this option")
 
 include(ParseConfigHeader)
 
 foreach(FLAG IN LISTS CONFIG_HEADER_FLAGS)
     string(REGEX MATCH "([^=]+)=(.+)" _ ${FLAG})
-    cmake_dependent_option(${CMAKE_MATCH_1} "" ${CMAKE_MATCH_2} CUSTOMIZE_BUILD ${CMAKE_MATCH_2})
+    set(CONFIG_HEADER_FLAG_DEFAULT ${CMAKE_MATCH_2})
+    if (INCLUDE_EVERYTHING AND "${CONFIG_HEADER_FLAG_DEFAULT}" STREQUAL "OFF")
+        set(CONFIG_HEADER_FLAG_DEFAULT ON)
+    endif()
+
+    cmake_dependent_option(${CMAKE_MATCH_1} "" ${CONFIG_HEADER_FLAG_DEFAULT} CUSTOMIZE_BUILD ${CONFIG_HEADER_FLAG_DEFAULT})
 endforeach()
diff --git a/cmake/ParseConfigHeader.cmake b/cmake/ParseConfigHeader.cmake
index 797eea3cd..6a4b96145 100644
--- a/cmake/ParseConfigHeader.cmake
+++ b/cmake/ParseConfigHeader.cmake
@@ -10,7 +10,9 @@ string(REGEX MATCHALL ${MACRO_REGEX} MACRO_LIST ${CONFIG_HEADER_CONTENT})
 set(CONFIG_HEADER_FLAGS ${MACRO_LIST})
 list(FILTER CONFIG_HEADER_FLAGS INCLUDE REGEX "^.+SUPPORT_")
 list(TRANSFORM CONFIG_HEADER_FLAGS REPLACE ${MACRO_REGEX} [[\2=OFF]] REGEX "^//")
-list(TRANSFORM CONFIG_HEADER_FLAGS REPLACE ${MACRO_REGEX} [[\2=ON]])
+list(TRANSFORM CONFIG_HEADER_FLAGS REPLACE ${MACRO_REGEX} [[\2=\3]] REGEX "^[^/]")
+list(TRANSFORM CONFIG_HEADER_FLAGS REPLACE [[=0$]] [[=OFF]])
+list(TRANSFORM CONFIG_HEADER_FLAGS REPLACE [[=1$]] [[=ON]])
 
 set(CONFIG_HEADER_VALUES ${MACRO_LIST})
 list(FILTER CONFIG_HEADER_VALUES EXCLUDE REGEX "(^.+SUPPORT_)|(^//)")