diff --git a/tools/Doxyfile b/tools/Doxyfile
index 1d2ea574..0f7d1fe6 100644
--- a/tools/Doxyfile
+++ b/tools/Doxyfile
@@ -753,7 +753,7 @@ WARN_LOGFILE           =
 # spaces.
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = ../src
+INPUT                  = ../src ../src/tests
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses