diff --git a/tests/Makefile b/tests/Makefile
index ad566572..d4fc1293 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -83,7 +83,7 @@ checkfail: fail-no-oplist
 
 # TODO: should grep failure message?
 fail-no-oplist:
-	for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ; do \
+	for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ; do \
 	if $(CC) $(CFLAGS) $(CPPFLAGS) -g -c fail-no-oplist.c -o tmp.o -DTEST=$$i 2> fail-no-oplist-$$i.log ; then echo FAILURE: fail-no-oplist-$$i ; false; else echo OK: fail-no-oplist-$$i ; fi \
 	done
 
diff --git a/tests/fail-no-oplist.c b/tests/fail-no-oplist.c
index 58e92e18..25d2adb7 100644
--- a/tests/fail-no-oplist.c
+++ b/tests/fail-no-oplist.c
@@ -121,6 +121,24 @@ BPTREE_MULTI_DEF2(tree, 4, int, DEFAULT_OPLIST, int, M_DEFAULT_OPLIST)
 
 BPTREE_MULTI_DEF(tree, 4, int, DEFAULT_OPLIST)
 
+#elif TEST == 18
+
+#include "m-buffer.h"
+
+BUFFER_DEF(buffer, int, 0, BUFFER_QUEUE, DEFAULT_OPLIST)
+
+#elif TEST == 19
+
+#include "m-buffer.h"
+
+QUEUE_MPMC_DEF(buffer, int, BUFFER_QUEUE, DEFAULT_OPLIST)
+
+#elif TEST == 20
+
+#include "m-buffer.h"
+
+QUEUE_SPSC_DEF(buffer, int, BUFFER_QUEUE, DEFAULT_OPLIST)
+
 #else
 # warning TEST variable is out of range.
 #endif