diff --git a/package.json b/package.json
index f9cb998..129e258 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "url": "https://github.com/aureooms/js-grammar/issues"
   },
   "dependencies": {
-    "@aureooms/js-itertools": "^4.0.1"
+    "@aureooms/js-itertools": "^5.0.0"
   },
   "devDependencies": {
     "@aureooms/js-compare": "1.4.8",
diff --git a/yarn.lock b/yarn.lock
index 274315f..7304e5c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,30 +2,30 @@
 # yarn lockfile v1
 
 
-"@aureooms/js-collections-deque@^4.0.1":
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/@aureooms/js-collections-deque/-/js-collections-deque-4.0.1.tgz#bd8b827cdb597d061525c380dd704e338c77bd5f"
-  integrity sha512-dktRVLyep0sUKpqgtG/JseA232KMdlu9t9ePq2wHcng1dZ3+63qW2C+FlKXBktrT1dU92DDxIL6PqnV97kHA1Q==
+"@aureooms/js-collections-deque@^6.0.1":
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-collections-deque/-/js-collections-deque-6.0.1.tgz#ba89379ac826539047f768e1fb84ed4d2c1f829e"
+  integrity sha512-GUhEIF6tmnxsGvUaPSR/7HbZETn04yHOcrt7swo5ftKRz+Pb/N9iuvGimBwmCTLDkJ60OZG2TWfoYPVNA2lutQ==
   dependencies:
-    "@aureooms/js-error" "^4.0.1"
+    "@aureooms/js-error" "^5.0.2"
 
 "@aureooms/js-compare@1.4.8":
   version "1.4.8"
   resolved "https://registry.yarnpkg.com/@aureooms/js-compare/-/js-compare-1.4.8.tgz#c6bff1091f4a2e211f449299572d9f195146fc59"
   integrity sha512-Z26PU6OmuhS7ZJsELTKImmipF7J+KCOyN70wBhhVIhmqUhXY6C3JpJHAev6wNBkC4ThlQt3zO6p/OmBFIq76Qg==
 
-"@aureooms/js-error@^4.0.1":
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/@aureooms/js-error/-/js-error-4.0.1.tgz#be2740b3f31a337e0828930c9b70d38113b4dd77"
-  integrity sha512-zsgs6wmnRsKljlusewYiBaFBM/hIJp43b7OwE9ybpLEL4wfXjGP17cJTTAY8gpzALVFwEA5/flxIK0I6gJJLHQ==
+"@aureooms/js-error@^5.0.2":
+  version "5.0.2"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-error/-/js-error-5.0.2.tgz#dc2ad2fc2b10365581c32c28222daccc5c3c9600"
+  integrity sha512-HLO95kmZ1nJV5qo8Xq7czHVskFGPkM3l60JFgdTnpvCH6P6lkyWDBplaDB9gI5cPvcRIZDs1HeAHhAlHR/jBxw==
 
-"@aureooms/js-itertools@^4.0.1":
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/@aureooms/js-itertools/-/js-itertools-4.0.1.tgz#6968eb71456daa042af0b8682100d59f397f7f91"
-  integrity sha512-cNaSF+5bgRGUXWBlWzSLjo0t12MHmkr1qCIxCvB4d3D5C7GPG0SH35efMOrv1VkHrLXuTqAbdnNu/iy2i26w5w==
+"@aureooms/js-itertools@^5.0.0":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@aureooms/js-itertools/-/js-itertools-5.0.1.tgz#73af47b0a710073730fccde6c57431a9178d1bea"
+  integrity sha512-EBmA0EiY49MSu7M6eCZvUyEhV79bvIQDg/LL3bfUG8fxhL4IeBLbgYc41a4/LunD5mLFG8ZQna/Z/oUjr4fUuQ==
   dependencies:
-    "@aureooms/js-collections-deque" "^4.0.1"
-    "@aureooms/js-error" "^4.0.1"
+    "@aureooms/js-collections-deque" "^6.0.1"
+    "@aureooms/js-error" "^5.0.2"
 
 "@aureooms/js-tape@7.0.0":
   version "7.0.0"