diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 2e202de..c57e14f 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -82,6 +82,10 @@
   set(CMAKE_C_FLAGS_CHECKFULL "${CMAKE_C_FLAGS_CHECK} -Wcast-qual")
 endif(CMAKE_COMPILER_IS_GNUCC)
 
+if(CMAKE_COMPILER_IS_CLANG)
+  set(CMAKE_C_FLAGS_CHECK "${CMAKE_C_FLAGS_CHECK} -Wmissing-declarations -Wmissing-prototypes")
+endif(CMAKE_COMPILER_IS_CLANG)
+
 if (NOT USE_STATIC_POLARSSL_LIBRARY AND NOT USE_SHARED_POLARSSL_LIBRARY)
 	message(FATAL_ERROR "Need to choose static or shared polarssl build!")
 endif(NOT USE_STATIC_POLARSSL_LIBRARY AND NOT USE_SHARED_POLARSSL_LIBRARY)