diff --git a/CMakeLists.txt b/CMakeLists.txt
index 53003b6..de9acdf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ link_libraries(ws2_32)
 if(MSVC)
   add_compile_options(/Wall /wd4127 /wd4201 /wd4242 /wd4710 /wd4711 /wd4820)
 else()
-  add_compile_options(-Wall)
+  add_compile_options(-Wall -Wextra)
 endif()
 
 file(GLOB SOURCES_SRC src/*.c src/*.h)