diff --git a/piker/clearing/_ems.py b/piker/clearing/_ems.py
index 429c1935..a4e40587 100644
--- a/piker/clearing/_ems.py
+++ b/piker/clearing/_ems.py
@@ -1247,7 +1247,7 @@ async def process_client_order_cmds(
                 pred = mk_check(trigger_price, last, action)
 
                 spread_slap: float = 5
-                min_tick = flume.symbol.size_tick
+                min_tick = float(flume.symbol.size_tick)
                 min_tick_digits = float_digits(min_tick)
 
                 if action == 'buy':