diff --git a/mex/sources/libkorder/tl/int_sequence.cc b/mex/sources/libkorder/tl/int_sequence.cc
index 09d6435adda8f30338a12e65a4b74c397a859e02..32a0736340887a00b9265fe431508494cdaadbf5 100644
--- a/mex/sources/libkorder/tl/int_sequence.cc
+++ b/mex/sources/libkorder/tl/int_sequence.cc
@@ -231,7 +231,7 @@ IntSequence::isConstant() const
 bool
 IntSequence::isSorted() const
 {
-  return std::is_sorted(data, data + length);
+  return std::ranges::is_sorted(data, data + length);
 }
 
 /* Debug print. */