diff --git a/DEPENDENCIES b/DEPENDENCIES
index 7632f321..e10c9644 100644
--- a/DEPENDENCIES
+++ b/DEPENDENCIES
@@ -1,6 +1,6 @@
 vendorpull https://github.com/sourcemeta/vendorpull dea311b5bfb53b6926a4140267959ae334d3ecf4
 noa https://github.com/sourcemeta/noa caad2e1ceedf9fd1a18686a6a6d1e2b9757ead75
-jsontoolkit https://github.com/sourcemeta/jsontoolkit a64204f6f69b12021bd1802143f61244f5ea9619
+jsontoolkit https://github.com/sourcemeta/jsontoolkit 117a478711f0aaec0e77a6bee3af0c5030340bb7
 googletest https://github.com/google/googletest a7f443b80b105f940225332ed3c31f2790092f47
 googlebenchmark https://github.com/google/benchmark 378fe693a1ef51500db21b11ff05a8018c5f0e55
 jsonschema-test-suite https://github.com/json-schema-org/JSON-Schema-Test-Suite c2badb1298a8698f86dadf1aea7b44b3a894e5ac
diff --git a/vendor/jsontoolkit/src/json/include/sourcemeta/jsontoolkit/json_object.h b/vendor/jsontoolkit/src/json/include/sourcemeta/jsontoolkit/json_object.h
index b9d2b774..6c376392 100644
--- a/vendor/jsontoolkit/src/json/include/sourcemeta/jsontoolkit/json_object.h
+++ b/vendor/jsontoolkit/src/json/include/sourcemeta/jsontoolkit/json_object.h
@@ -8,6 +8,22 @@
 #include <map> // std::map
 #else
 #include <unordered_map> // std::unordered_map
+
+// This hash function is specifically designed to be constant
+// with regards to string length, and to exploit the fact that
+// most JSON objects don't have a lot of entries, so hash collision
+// is not as common
+namespace sourcemeta::jsontoolkit {
+template <typename T> struct ObjectKeyHash {
+  inline auto operator()(const T &value) const noexcept -> std::size_t {
+    return value.empty()
+               ? 0
+               : value.size() + static_cast<std::size_t>(value.front()) +
+                     static_cast<std::size_t>(value.back());
+  }
+};
+} // namespace sourcemeta::jsontoolkit
+
 #endif
 
 namespace sourcemeta::jsontoolkit {
@@ -23,7 +39,7 @@ template <typename Key, typename Value> class JSONObject {
 #if defined(__GNUC__) && !defined(__clang__) && (__GNUC__ < 12)
       std::map<Key, Value, std::less<Key>,
 #else
-      std::unordered_map<Key, Value, std::hash<Key>, std::equal_to<Key>,
+      std::unordered_map<Key, Value, ObjectKeyHash<Key>, std::equal_to<Key>,
 #endif
                typename Value::template Allocator<
                    std::pair<const typename Value::String, Value>>>;