diff --git a/CMakeLists.txt b/CMakeLists.txt
index e6143bb7..7fe3f5fc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,6 +41,7 @@ if(BUILD_BOCHS)
   include_directories(simulators/bochs/instrument/stubs simulators/bochs)
 elseif(BUILD_GEM5)
   include_directories(simulators/gem5/src simulators/gem5/build/ARM)
+  SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DDEBUG -DTRACING_ON")
 elseif(BUILD_OVP)
   add_subdirectory(simulators/ovp)
 elseif(BUILD_QEMU)