diff --git a/CMakeLists.txt b/CMakeLists.txt
index a7daf19..b750180 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required (VERSION 2.8)
 project (w2rap-contigger)
 
 ## Compiler flags
-SET(CMAKE_CXX_FLAGS "-g -fopenmp -fpermissive -w -Wno-deprecated -std=c++11 -Ofast -lz")
+SET(CMAKE_CXX_FLAGS "-g -fopenmp -fpermissive -w -Wno-deprecated -std=c++11 -Ofast -lz -DNDEBUG")
 #SET(CMAKE_CXX_LINK_EXECUTABLE "/usr/bin/ld")
 add_definitions(${CMAKE_CXX_FLAGS})