diff --git a/docs/Doxygen.conf b/docs/Doxygen.conf
index 7e52f5198f..42d404cf18 100644
--- a/docs/Doxygen.conf
+++ b/docs/Doxygen.conf
@@ -83,7 +83,7 @@ WARN_LOGFILE           =
 #---------------------------------------------------------------------------
 # configuration options related to the input files
 #---------------------------------------------------------------------------
-INPUT                  = ../src ../src/include ../src/include/private
+INPUT                  = ../src ../src/include ../src/include/private ../libs/esl/src ../libs/esl/src/include
 FILE_PATTERNS          = *.c \
                          *.cc \
                          *.cxx \