diff --git a/coreapi/help/doc/doxygen/CMakeLists.txt b/coreapi/help/doc/doxygen/CMakeLists.txt
index a391509b5..a7bb34e2a 100644
--- a/coreapi/help/doc/doxygen/CMakeLists.txt
+++ b/coreapi/help/doc/doxygen/CMakeLists.txt
@@ -31,6 +31,7 @@ if (ENABLE_DOC OR ENABLE_CXX_WRAPPER OR ENABLE_CSHARP_WRAPPER)
 								${LINPHONE_HEADER_FILES}
 						)
 						add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/html/index.html" "${CMAKE_CURRENT_BINARY_DIR}/xml/index.xml"
+								COMMAND ${CMAKE_COMMAND} -E remove -f html/* xml/*
 								COMMAND ${DOXYGEN_EXECUTABLE} ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile
 								DEPENDS ${DOC_INPUT_FILES}
 						)