diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9770996b1..f5d6546a9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -124,6 +124,7 @@ endif ()
 
 # Predefined sets for OPTIMIZATION/OPENMP based on BUILD_TYPE
 if ("${CMAKE_BUILD_TYPE}" STREQUAL "DEBUG" OR "${CMAKE_BUILD_TYPE}" STREQUAL "SYNTAXONLY" )
+    set (DEBUG_FLAGS "${DEBUG_FLAGS} -DDEBUG")
     set (PARALLEL "OFF")
     set (OPTI "OFF")
 elseif ("${CMAKE_BUILD_TYPE}" STREQUAL "RELEASE")