diff --git a/src/hisp/bin.py b/src/hisp/bin.py
index 671c346e..478cefec 100644
--- a/src/hisp/bin.py
+++ b/src/hisp/bin.py
@@ -145,7 +145,7 @@ def set_inner_and_outer_bins(self) -> bool:
             outer_bin: True if outer bin
         """
         inner_swept_bins = list(range(45, 64))
-        outer_swept_bins = list(range(18, 33))
+        outer_swept_bins = list(range(18, 32))
 
         if self.index in inner_swept_bins:
             self.inner_bin = True