diff --git a/src/tt_um_ro_puf.v b/src/tt_um_ro_puf.v
index 072abd5..50ff46e 100644
--- a/src/tt_um_ro_puf.v
+++ b/src/tt_um_ro_puf.v
@@ -17,7 +17,6 @@ module tt_um_litneet64_ro_puf (
   assign rst = ~rst_n;
 
   // All output pins must be assigned. If not used, assign to 0.
-  assign uio_in = 8'b00000000;
   assign uio_out = 8'b00000000;
   assign uio_oe  = 8'b00000000;