diff --git a/artiq/gateware/targets/kc705.py b/artiq/gateware/targets/kc705.py
index d7672b435..502ca5902 100755
--- a/artiq/gateware/targets/kc705.py
+++ b/artiq/gateware/targets/kc705.py
@@ -229,8 +229,6 @@ class NIST_CLOCK(_NIST_Ions):
         rtio_channels.append(rtio.LogChannel())
 
         self.add_rtio(rtio_channels)
-        assert self.rtio.fine_ts_width <= 3
-        self.config["DDS_RTIO_CLK_RATIO"] = 24 >> self.rtio.fine_ts_width
 
 
 class NIST_QC2(_NIST_Ions):
@@ -309,8 +307,6 @@ class NIST_QC2(_NIST_Ions):
         rtio_channels.append(rtio.LogChannel())
 
         self.add_rtio(rtio_channels)
-        assert self.rtio.fine_ts_width <= 3
-        self.config["DDS_RTIO_CLK_RATIO"] = 24 >> self.rtio.fine_ts_width
 
 
 def main():