diff --git a/configure b/configure
index 00df1a1..94fc336 100755
--- a/configure
+++ b/configure
@@ -3499,6 +3499,10 @@ then
 
 $as_echo "#define DEBUG 1" >>confdefs.h
 
+else
+
+$as_echo "#define NDEBUG 1" >>confdefs.h
+
 fi
 
 ac_ext=c
diff --git a/configure.ac b/configure.ac
index 2e72058..fe49c0b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -40,6 +40,8 @@ then
    CFLAGS="${CFLAGS} -g"
    CXXFLAGS="${CXXFLAGS} -g"
    AC_DEFINE(DEBUG, 1, [Compile with debug code])
+else
+   AC_DEFINE(NDEBUG, 1, [Compile without debug code])
 fi
 
 dnl ###################