diff --git a/tests/Makefile.am b/tests/Makefile.am
index a41aabc..033ea23 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,5 +1,5 @@
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/tests
+AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/tests -UNDEBUG
 
 LDADD= $(LIBJSON_LA)