diff --git a/CMakeLists.txt b/CMakeLists.txt
index 015300fe..73d2aba7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -197,7 +197,7 @@ endif()
 
 if(CMAKE_BUILD_TYPE MATCHES Debug)
 if (CMAKE_COMPILER_IS_GNUCXX)
-	ADD_DEFINITIONS(-O3)
+	ADD_DEFINITIONS(-O0)
 	ADD_DEFINITIONS(-ggdb)
 	ADD_DEFINITIONS(-Wall)
 	ADD_DEFINITIONS(-W)