diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6cec8dc9..ab704fcc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -73,6 +73,9 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-switch-enum")
 endif()
 
+# Debug flags
+set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall -Wextra -Wundef")
+
 add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 add_definitions(-std=c++11)