diff --git a/examples/up5k_rgb/rgb.pcf b/examples/up5k_rgb/rgb.pcf
index 0954260..e390ba3 100644
--- a/examples/up5k_rgb/rgb.pcf
+++ b/examples/up5k_rgb/rgb.pcf
@@ -1,3 +1,4 @@
+set_frequency clk 32
 set_io RGB0 39
 set_io RGB1 40
 set_io RGB2 41