diff --git a/pixelflut.v b/pixelflut.v
index 886e8d7..ade8aca 100644
--- a/pixelflut.v
+++ b/pixelflut.v
@@ -27,10 +27,16 @@ module pixelflut (
 		end
 	end
 
+	reg dvi_bus_clk;
+
+	always @(posedge sys_clk) begin
+		dvi_bus_clk <= ~dvi_bus_clk;
+	end
+
 	wire [15:0] dvi_bus;
 
 	dvi display (
-		.bus_clk (sys_clk),
+		.bus_clk (dvi_bus_clk),
 		.bus_data(dvi_bus),
 		.bus_addr(dvi_bus),
 		.reset   (1'b0),