diff --git a/doxygen/Doxyfile b/doxygen/Doxyfile
index 8305e059..73e223bb 100644
--- a/doxygen/Doxyfile
+++ b/doxygen/Doxyfile
@@ -680,6 +680,7 @@ WARN_LOGFILE           = $(TRICK_HOME)/doxygen/warning_msgs
 
 INPUT                  = $(TRICK_HOME)/doxygen \
                          $(TRICK_HOME)/trick_source
+                         $(TRICK_HOME)/include
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is