diff --git a/verilog/sd2snes_test/main.ucf b/verilog/sd2snes_test/main.ucf
index 453ebf9..67fa757 100644
--- a/verilog/sd2snes_test/main.ucf
+++ b/verilog/sd2snes_test/main.ucf
@@ -535,6 +535,7 @@ NET "SD_DAT[3]" LOC = P63;
 # PlanAhead Generated IO constraints 
 
 NET "SD_CLK" IOSTANDARD = LVCMOS33;
+NET "SD_CLK" PULLUP;
 NET "SD_CMD" IOSTANDARD = LVCMOS33;
 NET "SD_DAT[0]" IOSTANDARD = LVCMOS33;
 NET "SD_DAT[1]" IOSTANDARD = LVCMOS33;