diff --git a/fpga_interchange/examples/lut/lut.xdc b/fpga_interchange/examples/lut/lut.xdc
index 4f7e948b..4f390f25 100644
--- a/fpga_interchange/examples/lut/lut.xdc
+++ b/fpga_interchange/examples/lut/lut.xdc
@@ -2,4 +2,6 @@ set_property PACKAGE_PIN N16 [get_ports i0]
 set_property PACKAGE_PIN N15 [get_ports i1]
 set_property PACKAGE_PIN M17 [get_ports o]
 
-#set_property IOSTANDARD LVCMOS33 [get_ports]
+set_property IOSTANDARD LVCMOS33 [get_ports i0]
+set_property IOSTANDARD LVCMOS33 [get_ports i1]
+set_property IOSTANDARD LVCMOS33 [get_ports o]