diff --git a/dap/algos/thresh.py b/dap/algos/thresh.py
index 66ac3b1..b1f6375 100644
--- a/dap/algos/thresh.py
+++ b/dap/algos/thresh.py
@@ -27,7 +27,7 @@ def calc_apply_threshold(results, data, value=None, copy=False):
 
 def threshold(data, vmin, vmax, replacement):
     """
-    threshold data in place by replacing values < vmin and values > vmax with replacement
+    threshold data in place by replacing values < vmin and values >= vmax with replacement
     """
     if vmin is not None and vmax is not None:
         # if vmin > vmax, data will be overwritten entirely -- better to ensure vmin < vmax by switching them if needed
@@ -35,7 +35,7 @@ def threshold(data, vmin, vmax, replacement):
     if vmin is not None:
         data[data < vmin] = replacement
     if vmax is not None:
-        data[data > vmax] = replacement
+        data[data >= vmax] = replacement