diff --git a/package.json b/package.json
index e8ebd23..67ebe59 100644
--- a/package.json
+++ b/package.json
@@ -78,28 +78,28 @@
   },
   "dependencies": {},
   "devDependencies": {
-    "@aureooms/js-array": "^4.0.0",
-    "@aureooms/js-compare": "^1.4.8",
-    "@aureooms/js-functools": "^2.0.3",
-    "@aureooms/js-itertools": "^4.1.0",
-    "@aureooms/js-memory": "^4.0.0",
-    "@aureooms/js-operator": "^1.0.2",
-    "@aureooms/js-random": "^2.0.0",
+    "@aureooms/js-array": "4.0.0",
+    "@aureooms/js-compare": "1.4.8",
+    "@aureooms/js-functools": "2.0.3",
+    "@aureooms/js-itertools": "4.1.0",
+    "@aureooms/js-memory": "4.0.0",
+    "@aureooms/js-operator": "1.0.2",
+    "@aureooms/js-random": "2.0.0",
     "@babel/cli": "7.12.10",
     "@babel/core": "7.12.10",
     "@babel/preset-env": "7.12.10",
     "@babel/register": "7.12.10",
-    "ava": "^3.14.0",
+    "ava": "3.14.0",
     "babel-plugin-transform-remove-console": "6.9.4",
     "babel-plugin-unassert": "3.0.1",
     "babel-preset-power-assert": "3.0.0",
-    "coveralls": "^3.1.0",
-    "esdoc": "^1.1.0",
+    "coveralls": "3.1.0",
+    "esdoc": "1.1.0",
     "esdoc-inject-script-plugin": "1.0.0",
     "esdoc-inject-style-plugin": "1.0.0",
     "esdoc-standard-plugin": "1.0.0",
     "np": "7.0.0",
-    "nyc": "^15.1.0",
+    "nyc": "15.1.0",
     "power-assert": "1.6.1"
   },
   "files": [
diff --git a/yarn.lock b/yarn.lock
index 8131c0f..efb6984 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,7 +2,7 @@
 # yarn lockfile v1
 
 
-"@aureooms/js-array@^4.0.0":
+"@aureooms/js-array@4.0.0":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@aureooms/js-array/-/js-array-4.0.0.tgz#ea64b7c788644f40bbb92259a6098ac14a4eca6c"
   integrity sha1-6mS3x4hkT0C7uSJZpgmKwUpOymw=
@@ -14,7 +14,7 @@
   dependencies:
     "@aureooms/js-error" "^4.0.1"
 
-"@aureooms/js-compare@^1.4.8":
+"@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==
@@ -24,12 +24,12 @@
   resolved "https://registry.yarnpkg.com/@aureooms/js-error/-/js-error-4.0.1.tgz#be2740b3f31a337e0828930c9b70d38113b4dd77"
   integrity sha512-zsgs6wmnRsKljlusewYiBaFBM/hIJp43b7OwE9ybpLEL4wfXjGP17cJTTAY8gpzALVFwEA5/flxIK0I6gJJLHQ==
 
-"@aureooms/js-functools@^2.0.3":
+"@aureooms/js-functools@2.0.3":
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/@aureooms/js-functools/-/js-functools-2.0.3.tgz#5139d6245278193da4cf21c44666797bf40a1d6e"
   integrity sha1-UTnWJFJ4GT2kzyHERmZ5e/QKHW4=
 
-"@aureooms/js-itertools@^4.1.0":
+"@aureooms/js-itertools@4.1.0":
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/@aureooms/js-itertools/-/js-itertools-4.1.0.tgz#c731eaee7de0005c6ea41f2f87cca4bdb2d86ca1"
   integrity sha512-P9TfwQPuXk5T5z6QMMfwLLyzh9QsEu4sGWcBk/P/waWgim/xqr+LDTOHVo7WU4QAty+/5CBX8DuW7MrPVfXt5A==
@@ -37,17 +37,17 @@
     "@aureooms/js-collections-deque" "^4.0.1"
     "@aureooms/js-error" "^4.0.1"
 
-"@aureooms/js-memory@^4.0.0":
+"@aureooms/js-memory@4.0.0":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@aureooms/js-memory/-/js-memory-4.0.0.tgz#db87dc64b948f672d73b434ebde047b05869712c"
   integrity sha1-24fcZLlI9nLXO0NOveBHsFhpcSw=
 
-"@aureooms/js-operator@^1.0.2":
+"@aureooms/js-operator@1.0.2":
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/@aureooms/js-operator/-/js-operator-1.0.2.tgz#0786d77d9977823ae7bc04360a315c45bb4c1e65"
   integrity sha1-B4bXfZl3gjrnvAQ2CjFcRbtMHmU=
 
-"@aureooms/js-random@^2.0.0":
+"@aureooms/js-random@2.0.0":
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@aureooms/js-random/-/js-random-2.0.0.tgz#f62c6954ed79bd9a520197125ee3cfbe14b00d72"
   integrity sha1-9ixpVO15vZpSAZcSXuPPvhSwDXI=
@@ -1288,7 +1288,7 @@ atob@^2.1.2:
   resolved "https://registry.yarnpkg.com/atob/-/atob-2.1.2.tgz#6d9517eb9e030d2436666651e86bd9f6f13533c9"
   integrity sha512-Wm6ukoaOGJi/73p/cl2GvLjTI5JM1k/O14isD73YML8StrH/7/lRFgmg8nICZgD3bZZvjwCGxtMOD3wWNAu8cg==
 
-ava@^3.14.0:
+ava@3.14.0:
   version "3.14.0"
   resolved "https://registry.yarnpkg.com/ava/-/ava-3.14.0.tgz#d519bc9abce9a44ead34c86b98bbe72771a6bd81"
   integrity sha512-AkXNi3DBXZE8A1z1JiNvdK6WmpN8oJQcZLkaWU24C3knCN9WVaxoDy90IVQlwjjPySeyQFqWDrsW9KomSNlRmQ==
@@ -2087,7 +2087,7 @@ cosmiconfig@^7.0.0:
     path-type "^4.0.0"
     yaml "^1.10.0"
 
-coveralls@^3.1.0:
+coveralls@3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/coveralls/-/coveralls-3.1.0.tgz#13c754d5e7a2dd8b44fe5269e21ca394fb4d615b"
   integrity sha512-sHxOu2ELzW8/NC1UP5XVLbZDzO4S3VxfFye3XYCznopHy02YjNkHcj5bKaVw2O7hVaBdBjEdQGpie4II1mWhuQ==
@@ -2667,7 +2667,7 @@ esdoc-unexported-identifier-plugin@^1.0.0:
   resolved "https://registry.yarnpkg.com/esdoc-unexported-identifier-plugin/-/esdoc-unexported-identifier-plugin-1.0.0.tgz#1f9874c6a7c2bebf9ad397c3ceb75c9c69dabab1"
   integrity sha1-H5h0xqfCvr+a05fDzrdcnGnaurE=
 
-esdoc@^1.1.0:
+esdoc@1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/esdoc/-/esdoc-1.1.0.tgz#07d40ebf791764cd537929c29111e20a857624f3"
   integrity sha512-vsUcp52XJkOWg9m1vDYplGZN2iDzvmjDL5M/Mp8qkoDG3p2s0yIQCIjKR5wfPBaM3eV14a6zhQNYiNTCVzPnxA==
@@ -4670,7 +4670,7 @@ number-is-nan@^1.0.0:
   resolved "https://registry.yarnpkg.com/nwmatcher/-/nwmatcher-1.4.4.tgz#2285631f34a95f0d0395cd900c96ed39b58f346e"
   integrity sha512-3iuY4N5dhgMpCUrOVnuAdGrgxVqV2cJpM+XNccjR2DKOB1RUP0aA+wGXEiNziG/UKboFyGBIoKOaNlJxx8bciQ==
 
-nyc@^15.1.0:
+nyc@15.1.0:
   version "15.1.0"
   resolved "https://registry.yarnpkg.com/nyc/-/nyc-15.1.0.tgz#1335dae12ddc87b6e249d5a1994ca4bdaea75f02"
   integrity sha512-jMW04n9SxKdKi1ZMGhvUTHBN0EICCRkHemEoE5jm6mTYcqcdas0ATzgUgejlQUHMvpnOZqGB5Xxsv9KxJW1j8A==