diff --git a/scripts/build.docs.doxygen/Doxyfile.in b/scripts/build.docs.doxygen/Doxyfile.in
index 51f9bd4..071a08c 100644
--- a/scripts/build.docs.doxygen/Doxyfile.in
+++ b/scripts/build.docs.doxygen/Doxyfile.in
@@ -140,12 +140,13 @@ PERLMOD_LATEX          = NO
 PERLMOD_PRETTY         = YES
 PERLMOD_MAKEVAR_PREFIX = 
 ENABLE_PREPROCESSING   = YES
-MACRO_EXPANSION        = NO
-EXPAND_ONLY_PREDEF     = NO
+MACRO_EXPANSION        = YES
+EXPAND_ONLY_PREDEF     = YES
 SEARCH_INCLUDES        = YES
 INCLUDE_PATH           =
 INCLUDE_FILE_PATTERNS  =
-PREDEFINED             = DOXYGEN
+PREDEFINED             = DOXYGEN \
+                         __attribute__()=
 EXPAND_AS_DEFINED      =
 SKIP_FUNCTION_MACROS   = YES
 TAGFILES               =