diff --git a/CMakeLists.txt b/CMakeLists.txt
index aeb96d6d..24b1d79f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -279,7 +279,6 @@ endif()
 if(CMAKE_BUILD_TYPE STREQUAL "Debug" OR CMAKE_BUILD_TYPE STREQUAL "debug")
     set(BUILD_DEBUG ON)
     set(CMAKE_VERBOSE_MAKEFILE ON)
-    set(DEBUG_OPTIMIZATION "-O3")
 endif()
 if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "release")
     set(BUILD_RELEASE ON)
@@ -398,7 +397,6 @@ else()
 
     set(CMAKE_C_FLAGS_DEBUG
             "${CMAKE_C_FLAGS_DEBUG} \
-         ${DEBUG_OPTIMIZATION} \
          -DLWIP_DEBUG=1 -DLIBZT_DEBUG=1")
 
     set(CMAKE_C_FLAGS_RELEASE
@@ -411,7 +409,6 @@ else()
 
     set(CMAKE_CXX_FLAGS_DEBUG
             "${CMAKE_CXX_FLAGS_DEBUG} \
-         ${DEBUG_OPTIMIZATION} \
          -DLWIP_DEBUG=1 -DLIBZT_DEBUG=1")
 
     set(CMAKE_CXX_FLAGS_RELEASE