diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index 950f49b..78b7570 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -1,5 +1,5 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2020, Arm Limited. All rights reserved.
+# Copyright (c) 2020-2021, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -49,7 +49,7 @@
 
     add_custom_command(OUTPUT "${SPHINXCFG_OUTPUT_PATH}/html/index.html"
         OUTPUT "${SPHINXCFG_OUTPUT_PATH}/html/"
-        COMMAND "${SPHINX_EXECUTABLE}" -b html "${SPHINX_TMP_DOC_DIR}" "${SPHINXCFG_OUTPUT_PATH}/html"
+        COMMAND "${SPHINX_EXECUTABLE}" -W -b html "${SPHINX_TMP_DOC_DIR}" "${SPHINXCFG_OUTPUT_PATH}/html"
         WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
         DEPENDS tfm_docs_sphinx_cfg
         DEPENDS ${SPHINXCFG_DOC_FILES}