diff --git a/tests/simple_abc9/abc9.box b/tests/simple_abc9/abc9.box
new file mode 100644
index 000000000..b3c88437c
--- /dev/null
+++ b/tests/simple_abc9/abc9.box
@@ -0,0 +1,3 @@
+MUXF8 1 0 3 1
+#I0 I1 S
+0 0 0 # O
diff --git a/tests/simple_abc9/abc9.v b/tests/simple_abc9/abc9.v
index 688b47586..5e969c614 100644
--- a/tests/simple_abc9/abc9.v
+++ b/tests/simple_abc9/abc9.v
@@ -213,7 +213,7 @@ module arbiter (clk, rst, request, acknowledge, grant, grant_valid, grant_encode
   input rst;
 endmodule
 
-(* abc9_box, blackbox *)
+(* abc9_box_id=1, blackbox *)
 module MUXF8(input I0, I1, S, output O);
 specify
     (I0 => O) = 0;
diff --git a/tests/simple_abc9/run-test.sh b/tests/simple_abc9/run-test.sh
index 424d8f417..650e42fca 100755
--- a/tests/simple_abc9/run-test.sh
+++ b/tests/simple_abc9/run-test.sh
@@ -25,7 +25,7 @@ exec ${MAKE:-make} -f ../tools/autotest.mk $seed *.v *.sv EXTRA_FLAGS="-n 300 -p
     synth -run coarse; \
     opt -full; \
     techmap; \
-    abc9 -lut 4; \
+    abc9 -lut 4 -box ../abc9.box; \
     clean; \
     check -assert; \
     select -assert-none t:${DOLLAR}_NOT_ t:${DOLLAR}_AND_ %%; \