diff --git a/commands/cleantmp/cleantmp.c b/commands/cleantmp/cleantmp.c
index 3c4d5a9c6..a6018fde6 100644
--- a/commands/cleantmp/cleantmp.c
+++ b/commands/cleantmp/cleantmp.c
@@ -22,8 +22,10 @@
 #endif
 
 #ifndef DEBUG
+#ifndef NDEBUG
 #define NDEBUG
 #endif
+#endif
 #include <assert.h>
 
 #define SEC_DAY	(24 * 3600L)	/* A full day in seconds */