diff --git a/src/test/tests_list.c b/src/test/tests_list.c
index 5e6c2fa9..e7e847ef 100644
--- a/src/test/tests_list.c
+++ b/src/test/tests_list.c
@@ -33,6 +33,7 @@
 #include <getdns/getdns.h>
 
 #define TSTMSGBUF 80
+#define GETDNS_LIST_BLOCKSZ 10
 
 /* TODO: might want a separate unit test for getdns_list_copy() - right now the code gets
    covered as a result of other tests */