diff --git a/Doxyfile.in b/Doxyfile.in
index f79aa79..fa0d57b 100644
--- a/Doxyfile.in
+++ b/Doxyfile.in
@@ -40,4 +40,5 @@ HTML_TIMESTAMP         = YES
 GENERATE_LATEX         = NO
 
 # Assume source preprocessed with all subsystems enable
-PREDEFINED             = SDL2PP_WITH_IMAGE SDL2PP_WITH_MIXER SDL2PP_WITH_TTF
+# Also enable all conditionals based on SDL version
+PREDEFINED             = SDL2PP_WITH_IMAGE SDL2PP_WITH_MIXER SDL2PP_WITH_TTF SDL_VERSION_ATLEAST(X,Y,Z)=1