--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -91,16 +91,6 @@ add_check_c_cxx_flag("-Wredundant-decls")
 add_check_c_flag("-std=gnu99")
 add_required_cxx_flag("-std=gnu++11")
 
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-  add_check_c_cxx_flag("-g3")
-  add_check_c_cxx_flag("-ggdb")
-else()
-  add_check_c_cxx_flag("-O3")
-  if(NOT CHECK)
-    add_check_c_cxx_flag("-DNDEBUG")
-  endif()
-endif()
-
 if(ASAN)
   # -fsanitize=address requires CMAKE_REQUIRED_FLAGS to be explicitely set,
   # otherwise the -fsanitize=address check will fail while linking.