diff --git a/fsm/rtl/top.v b/fsm/rtl/top.v
index 0709da2..d4acbd3 100644
--- a/fsm/rtl/top.v
+++ b/fsm/rtl/top.v
@@ -32,8 +32,8 @@ module top(i_clk, o_led, lcol1);
          obuf <= {obuf[6:0], obuf[7]}; // left shift
          // obuf <= {obuf[0], obuf[7:1]}; // right shift
 
-   always @(*)
-      o_led = ~obuf;
+   always @(posedge clk_12MHz)
+      o_led <= ~obuf;
 
    assign lcol1 = 1'b0;
 endmodule