diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 1116a58..57ebf83 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -82,7 +82,7 @@
 endif(CMAKE_COMPILER_IS_GNUCC)
 
 if(CMAKE_COMPILER_IS_CLANG)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations -Wmissing-prototypes -Wdocumentation -Wunreachable-code")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations -Wmissing-prototypes -Wdocumentation -Wno-documentation-deprecated-sync -Wunreachable-code")
 endif(CMAKE_COMPILER_IS_CLANG)
 
 if (NOT USE_STATIC_MBEDTLS_LIBRARY AND NOT USE_SHARED_MBEDTLS_LIBRARY)