diff --git a/doxygen/Doxyfile.in b/doxygen/Doxyfile.in
index af15c5b..9a1e475 100644
--- a/doxygen/Doxyfile.in
+++ b/doxygen/Doxyfile.in
@@ -2073,7 +2073,8 @@
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-PREDEFINED             = __attribute__(x)=
+PREDEFINED             = __attribute__(x)= \
+                         __DOXYGEN_ONLY__
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The