add default nettype none
diff --git a/verilog/rtl/digital_pll.v b/verilog/rtl/digital_pll.v
index 06ceaf9..dac708a 100644
--- a/verilog/rtl/digital_pll.v
+++ b/verilog/rtl/digital_pll.v
@@ -1,3 +1,4 @@
+`default_nettype none
 // Digital PLL (ring oscillator + controller)
 // Technically this is a frequency locked loop, not a phase locked loop.