diff --git a/artiq/coredevice/coredevice_generic.schema.json b/artiq/coredevice/coredevice_generic.schema.json
index 66b54d5fc..a695c3850 100644
--- a/artiq/coredevice/coredevice_generic.schema.json
+++ b/artiq/coredevice/coredevice_generic.schema.json
@@ -308,7 +308,8 @@
                         "clk_div": {
                             "type": "integer",
                             "minimum": 0,
-                            "maximum": 3
+                            "maximum": 3,
+                            "default": 0
                         },
                         "pll_n": {
                             "type": "integer"
diff --git a/artiq/frontend/artiq_ddb_template.py b/artiq/frontend/artiq_ddb_template.py
index 40e193e8f..15dcbf642 100755
--- a/artiq/frontend/artiq_ddb_template.py
+++ b/artiq/frontend/artiq_ddb_template.py
@@ -232,13 +232,15 @@ class PeripheralManager:
                     "sync_device": {sync_device},
                     "io_update_device": "ttl_{name}_io_update",
                     "refclk": {refclk},
-                    "clk_sel": {clk_sel}
+                    "clk_sel": {clk_sel},
+                    "clk_div": {clk_div}
                 }}
             }}""",
             name=urukul_name,
             sync_device="\"ttl_{name}_sync\"".format(name=urukul_name) if synchronization else "None",
             refclk=peripheral.get("refclk", self.primary_description["rtio_frequency"]),
-            clk_sel=peripheral["clk_sel"])
+            clk_sel=peripheral["clk_sel"],
+            clk_div=peripheral["clk_div"])
         dds = peripheral["dds"]
         pll_vco = peripheral.get("pll_vco")
         for i in range(4):