diff --git a/src/amd/compiler/aco_util.h b/src/amd/compiler/aco_util.h
index 910feb0ca9c..2cceeb3c314 100644
--- a/src/amd/compiler/aco_util.h
+++ b/src/amd/compiler/aco_util.h
@@ -21,6 +21,7 @@
 #include <memory>
 #include <type_traits>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 namespace aco {
@@ -391,6 +392,14 @@ template <class Key, class T, class Hash = std::hash<Key>, class Pred = std::equ
 using unordered_map =
    std::unordered_map<Key, T, Hash, Pred, aco::monotonic_allocator<std::pair<const Key, T>>>;
 
+/*
+ * aco::unordered_set - alias for std::unordered_set with monotonic_allocator
+ *
+ * This template specialization mimics std::pmr::unordered_set.
+ */
+template <class T, class Hash = std::hash<T>, class Pred = std::equal_to<T>>
+using unordered_set = std::unordered_set<T, Hash, Pred, aco::monotonic_allocator<T>>;
+
 /*
  * Cache-friendly set of 32-bit IDs with fast insert/erase/lookup and
  * the ability to efficiently iterate over contained elements.