diff --git a/GNUmakefile b/GNUmakefile
index 21be765d..69be3c2b 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -70,7 +70,7 @@ MES:=./mes
 MES_FLAGS:=--load
 export MES_FLAGS
 MES_DEBUG:=1
-export MES_DEBUG
+#export MES_DEBUG
 
 mes-check: all
 	set -e; for i in $(TESTS); do ./$$i; done