diff --git a/piker/data/_m4.py b/piker/data/_m4.py
index 26d5e0b0..f75d3209 100644
--- a/piker/data/_m4.py
+++ b/piker/data/_m4.py
@@ -90,8 +90,6 @@ def ds_m4(
     if xrange is None:
         x_end = x[-1]  # x end value/highest in domain
         xrange = (x_end - x_start)
-        if xrange < 0:
-            breakpoint()
 
     # XXX: always round up on the input pixels
     # lnx = len(x)