diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index b60575a933bbe4680558328e1dd9c98160d3a1aa..a523da466c9a34479f06965b0b4334166cc2d645 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -26,7 +26,7 @@ file(GLOB_RECURSE ALL_PUBLIC_HEADERS ${ALL_PUBLIC_HEADER_DIR})
 
 # setup configuring of doxygen
 # Caveat(s.schulz): Make sure there are not spaces within the paths.
-set(DOXYGEN_INPUT_DIR ${PROJECT_SOURCE_DIR}/include ${PROJECT_SOURCE_DIR}/src ${PROJECT_SOURCE_DIR}/example ${PROJECT_SOURCE_DIR}/README.md)
+set(DOXYGEN_INPUT_DIR ${PROJECT_SOURCE_DIR}/include ${PROJECT_SOURCE_DIR}/src ${PROJECT_SOURCE_DIR}/example ${PROJECT_SOURCE_DIR}/tests/feature ${PROJECT_SOURCE_DIR}/tests/unit ${PROJECT_SOURCE_DIR}/README.md)
 string(REPLACE ";" "\" \"" DOXYGEN_INPUT_DIR "${DOXYGEN_INPUT_DIR}")
 set(DOXYGEN_OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}/doc/doxygen)
 set(DOXYGEN_INDEX_FILE ${DOXYGEN_OUTPUT_DIR}/xml/index.xml)