diff --git a/techlibs/xilinx/Makefile.inc b/techlibs/xilinx/Makefile.inc
index d68f03bb4..9937c0c9c 100644
--- a/techlibs/xilinx/Makefile.inc
+++ b/techlibs/xilinx/Makefile.inc
@@ -30,6 +30,7 @@ $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/drams_map.v))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/arith_map.v))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/ff_map.v))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/lut_map.v))
+$(eval $(call add_share_file,share/xilinx,techlibs/xilinx/cells.box))
 
 $(eval $(call add_gen_share_file,share/xilinx,techlibs/xilinx/brams_init_36.vh))
 $(eval $(call add_gen_share_file,share/xilinx,techlibs/xilinx/brams_init_32.vh))
diff --git a/techlibs/xilinx/cells.box b/techlibs/xilinx/cells.box
new file mode 100644
index 000000000..31ad4a656
--- /dev/null
+++ b/techlibs/xilinx/cells.box
@@ -0,0 +1,5 @@
+MUXF7 1 0 2 1
+1 1
+
+MUXF8 2 0 2 1
+1 1