diff --git a/verilog/m1crg/m1crg.v b/verilog/m1crg/m1crg.v
index 23ccf0bce..d5582d405 100644
--- a/verilog/m1crg/m1crg.v
+++ b/verilog/m1crg/m1crg.v
@@ -263,7 +263,7 @@ DCM_CLKGEN #(
 	.CLKFX_DIVIDE(4),
 	.CLKFX_MD_MAX(2.0),
 	.CLKFX_MULTIPLY(2),
-	.CLKIN_PERIOD(0.0),
+	.CLKIN_PERIOD(20.0),
 	.SPREAD_SPECTRUM("NONE"),
 	.STARTUP_WAIT("FALSE")
 ) vga_clock_gen (