diff --git a/massdash/structs/Data1D.py b/massdash/structs/Data1D.py
index c23d3ff9..f85d55d7 100644
--- a/massdash/structs/Data1D.py
+++ b/massdash/structs/Data1D.py
@@ -132,7 +132,7 @@ def adjust_length(self, length):
                 slice_left = slice_right = excess_length // 2
             else: # length % 2 == 1
                 slice_left = excess_length // 2
-                slice_right = excess_length + 1 // 2
+                slice_right = (excess_length + 1) // 2
             new_data = self.data[slice_left:-slice_right]
             new_intensity = self.intensity[slice_left:-slice_right]
         else: # length > len(self.data):