diff --git a/port/posix-h4/CMakeLists.txt b/port/posix-h4/CMakeLists.txt
index 8161d0057..938d51115 100644
--- a/port/posix-h4/CMakeLists.txt
+++ b/port/posix-h4/CMakeLists.txt
@@ -7,10 +7,10 @@ SET(BTSTACK_ROOT ${CMAKE_SOURCE_DIR}/../..)
 # extra compiler warnings
 if ("${CMAKE_C_COMPILER_ID}" MATCHES ".*Clang.*")
 	# using Clang
-	SET(CMAKE_C_FLAGS  "${CMAKE_C_FLAGS} -Wunused-variable -Wswitch-default -Werror")
+    SET(CMAKE_C_FLAGS  "${CMAKE_C_FLAGS} -Wunused-variable -Wswitch-default -Wall -Wextra -Werror")
 elseif ("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU")
 	# using GCC
-	SET(CMAKE_C_FLAGS  "${CMAKE_C_FLAGS} -Wunused-but-set-variable -Wunused-variable -Wswitch-default -Werror")
+    SET(CMAKE_C_FLAGS  "${CMAKE_C_FLAGS} -Wunused-but-set-variable -Wunused-variable -Wswitch-default -Wall -Wextra -Werror")
 elseif ("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel")
 	# using Intel C++
 elseif ("${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC")