diff --git a/cpdctrl/led_script.py b/cpdctrl/led_script.py
index 85405cb..e1ee035 100644
--- a/cpdctrl/led_script.py
+++ b/cpdctrl/led_script.py
@@ -292,8 +292,8 @@ class LedScript:
             raise InvalidScriptUpdate(f"Cannot update row {idx+1} the script only has {n_rows} rows")
         if not (led >= 0 and led <= 100):
             raise InvalidScriptUpdate(f"Cannot update row {idx+1} because the led value {led}% is not in the range of 0%-100%")
-        if not (dt > 0):
-            raise InvalidScriptUpdate(f"Cannot update row {idx+1} because the dt value '{dt}' <= 0")
+        if dt < 0:
+            raise InvalidScriptUpdate(f"Cannot update row {idx+1} because the dt value '{dt}' < 0")
         if self.current_dt:
             current_idx = self.get_current_index(self.current_dt)
             if current_idx < idx: