diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index f6776ed..1e09d31 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -89,11 +89,11 @@
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCC)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations")
+    set(LIBS_C_FLAGS -Wmissing-declarations)
 endif(CMAKE_COMPILER_IS_GNUCC)
 
 if(CMAKE_COMPILER_IS_CLANG)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wmissing-declarations -Wdocumentation -Wno-documentation-deprecated-sync -Wunreachable-code")
+    set(LIBS_C_FLAGS -Wmissing-declarations -Wdocumentation -Wno-documentation-deprecated-sync -Wunreachable-code)
 endif(CMAKE_COMPILER_IS_CLANG)
 
 if(CMAKE_COMPILER_IS_MSVC)
@@ -154,11 +154,13 @@
 if(USE_STATIC_MBEDTLS_LIBRARY)
     add_library(${mbedx509_static_target} STATIC ${src_x509})
     set_base_compile_options(${mbedx509_static_target})
+    target_compile_options(${mbedx509_static_target} PRIVATE ${LIBS_C_FLAGS})
     set_target_properties(${mbedx509_static_target} PROPERTIES OUTPUT_NAME mbedx509)
     target_link_libraries(${mbedx509_static_target} PUBLIC ${libs} ${mbedcrypto_static_target})
 
     add_library(${mbedtls_static_target} STATIC ${src_tls})
     set_base_compile_options(${mbedtls_static_target})
+    target_compile_options(${mbedtls_static_target} PRIVATE ${LIBS_C_FLAGS})
     set_target_properties(${mbedtls_static_target} PROPERTIES OUTPUT_NAME mbedtls)
     target_link_libraries(${mbedtls_static_target} PUBLIC ${libs} ${mbedx509_static_target})
 endif(USE_STATIC_MBEDTLS_LIBRARY)
@@ -166,11 +168,13 @@
 if(USE_SHARED_MBEDTLS_LIBRARY)
     add_library(${mbedx509_target} SHARED ${src_x509})
     set_base_compile_options(${mbedx509_target})
+    target_compile_options(${mbedx509_target} PRIVATE ${LIBS_C_FLAGS})
     set_target_properties(${mbedx509_target} PROPERTIES VERSION 4.0.0 SOVERSION 7)
     target_link_libraries(${mbedx509_target} PUBLIC ${libs} ${mbedcrypto_target})
 
     add_library(${mbedtls_target} SHARED ${src_tls})
     set_base_compile_options(${mbedtls_target})
+    target_compile_options(${mbedtls_target} PRIVATE ${LIBS_C_FLAGS})
     set_target_properties(${mbedtls_target} PROPERTIES VERSION 4.0.0 SOVERSION 21)
     target_link_libraries(${mbedtls_target} PUBLIC ${libs} ${mbedx509_target})
 endif(USE_SHARED_MBEDTLS_LIBRARY)