diff --git a/packages/mkcmdargv-cli/package.json b/packages/mkcmdargv-cli/package.json
index ab5acee3..ccaca56a 100644
--- a/packages/mkcmdargv-cli/package.json
+++ b/packages/mkcmdargv-cli/package.json
@@ -15,10 +15,10 @@
   "sideEffects": false,
   "bin": "bin",
   "dependencies": {
-    "js-yaml": "^3.14.0",
+    "js-yaml": "^4.0.0",
     "tslib": "^2.0.1",
     "mkcmdargv-lib": "^0.1.5",
-    "@types/js-yaml": "^3.12.5",
+    "@types/js-yaml": "^4.0.0",
     "@types/node": "^14.6.0"
   }
 }
diff --git a/packages/mkcmdargv-cli/pnpm-lock.yaml b/packages/mkcmdargv-cli/pnpm-lock.yaml
index 3b67f96a..3a4808c5 100644
--- a/packages/mkcmdargv-cli/pnpm-lock.yaml
+++ b/packages/mkcmdargv-cli/pnpm-lock.yaml
@@ -1,51 +1,38 @@
 lockfileVersion: 5.3
 
 specifiers:
-  '@types/js-yaml': ^3.12.5
+  '@types/js-yaml': ^4.0.0
   '@types/node': ^14.6.0
-  js-yaml: ^3.14.0
+  js-yaml: ^4.0.0
   mkcmdargv-lib: ^0.1.5
   tslib: ^2.0.1
 
 dependencies:
-  '@types/js-yaml': 3.12.5
+  '@types/js-yaml': 4.0.5
   '@types/node': 14.6.0
-  js-yaml: 3.14.0
+  js-yaml: 4.1.0
   mkcmdargv-lib: link:../mkcmdargv-lib
   tslib: 2.0.1
 
 packages:
 
-  /@types/js-yaml/3.12.5:
-    resolution: {integrity: sha512-JCcp6J0GV66Y4ZMDAQCXot4xprYB+Zfd3meK9+INSJeVZwJmHAW30BBEEkPzXswMXuiyReUGOP3GxrADc9wPww==}
+  /@types/js-yaml/4.0.5:
+    resolution: {integrity: sha512-FhpRzf927MNQdRZP0J5DLIdTXhjLYzeUTmLAu69mnVksLH9CJY3IuSeEgbKUki7GQZm0WqDkGzyxju2EZGD2wA==}
     dev: false
 
   /@types/node/14.6.0:
     resolution: {integrity: sha512-mikldZQitV94akrc4sCcSjtJfsTKt4p+e/s0AGscVA6XArQ9kFclP+ZiYUMnq987rc6QlYxXv/EivqlfSLxpKA==}
     dev: false
 
-  /argparse/1.0.10:
-    resolution: {integrity: sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==}
-    dependencies:
-      sprintf-js: 1.0.3
-    dev: false
-
-  /esprima/4.0.1:
-    resolution: {integrity: sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==}
-    engines: {node: '>=4'}
-    hasBin: true
+  /argparse/2.0.1:
+    resolution: {integrity: sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==}
     dev: false
 
-  /js-yaml/3.14.0:
-    resolution: {integrity: sha512-/4IbIeHcD9VMHFqDR/gQ7EdZdLimOvW2DdcxFjdyyZ9NsbS+ccrXqVWDtab/lRl5AlUqmpBx8EhPaWR+OtY17A==}
+  /js-yaml/4.1.0:
+    resolution: {integrity: sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==}
     hasBin: true
     dependencies:
-      argparse: 1.0.10
-      esprima: 4.0.1
-    dev: false
-
-  /sprintf-js/1.0.3:
-    resolution: {integrity: sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw=}
+      argparse: 2.0.1
     dev: false
 
   /tslib/2.0.1:
diff --git a/tools/ignore-file/package.json b/tools/ignore-file/package.json
index b63891d4..42cf0dff 100644
--- a/tools/ignore-file/package.json
+++ b/tools/ignore-file/package.json
@@ -8,12 +8,12 @@
   },
   "dependencies": {
     "minimatch": "^3.0.4",
-    "js-yaml": "^3.14.0",
+    "js-yaml": "^4.0.0",
     "fs-extra": "^10.0.0",
     "fs-tree-utils": "^0.1.8",
     "tslib": "^2.0.1",
     "@types/minimatch": "^3.0.3",
-    "@types/js-yaml": "^3.12.5",
+    "@types/js-yaml": "^4.0.0",
     "@types/fs-extra": "^9.0.1",
     "@tools/preloaded-node": "file:../preloaded-node",
     "@tools/places": "file:../places"
diff --git a/tools/ignore-file/pnpm-lock.yaml b/tools/ignore-file/pnpm-lock.yaml
index 7a2fbd5d..f2c9342d 100644
--- a/tools/ignore-file/pnpm-lock.yaml
+++ b/tools/ignore-file/pnpm-lock.yaml
@@ -4,11 +4,11 @@ specifiers:
   '@tools/places': file:../places
   '@tools/preloaded-node': file:../preloaded-node
   '@types/fs-extra': ^9.0.1
-  '@types/js-yaml': ^3.12.5
+  '@types/js-yaml': ^4.0.0
   '@types/minimatch': ^3.0.3
   fs-extra: ^10.0.0
   fs-tree-utils: ^0.1.8
-  js-yaml: ^3.14.0
+  js-yaml: ^4.0.0
   minimatch: ^3.0.4
   tslib: ^2.0.1
 
@@ -16,11 +16,11 @@ dependencies:
   '@tools/places': link:../places
   '@tools/preloaded-node': link:../preloaded-node
   '@types/fs-extra': 9.0.1
-  '@types/js-yaml': 3.12.5
+  '@types/js-yaml': 4.0.5
   '@types/minimatch': 3.0.3
   fs-extra: 10.0.0
   fs-tree-utils: 0.1.8
-  js-yaml: 3.14.0
+  js-yaml: 4.1.0
   minimatch: 3.0.4
   tslib: 2.0.1
 
@@ -45,8 +45,8 @@ packages:
       '@types/node': 14.0.6
     dev: false
 
-  /@types/js-yaml/3.12.5:
-    resolution: {integrity: sha512-JCcp6J0GV66Y4ZMDAQCXot4xprYB+Zfd3meK9+INSJeVZwJmHAW30BBEEkPzXswMXuiyReUGOP3GxrADc9wPww==}
+  /@types/js-yaml/4.0.5:
+    resolution: {integrity: sha512-FhpRzf927MNQdRZP0J5DLIdTXhjLYzeUTmLAu69mnVksLH9CJY3IuSeEgbKUki7GQZm0WqDkGzyxju2EZGD2wA==}
     dev: false
 
   /@types/minimatch/3.0.3:
@@ -61,10 +61,8 @@ packages:
     resolution: {integrity: sha512-FbNmu4F67d3oZMWBV6Y4MaPER+0EpE9eIYf2yaHhCWovc1dlXCZkqGX4NLHfVVr6umt20TNBdRzrNJIzIKfdbw==}
     dev: false
 
-  /argparse/1.0.10:
-    resolution: {integrity: sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==}
-    dependencies:
-      sprintf-js: 1.0.3
+  /argparse/2.0.1:
+    resolution: {integrity: sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==}
     dev: false
 
   /balanced-match/1.0.0:
@@ -82,12 +80,6 @@ packages:
     resolution: {integrity: sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=}
     dev: false
 
-  /esprima/4.0.1:
-    resolution: {integrity: sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==}
-    engines: {node: '>=4'}
-    hasBin: true
-    dev: false
-
   /fs-extra/10.0.0:
     resolution: {integrity: sha512-C5owb14u9eJwizKGdchcDUQeFtlSHHthBk8pbX9Vc1PFZrLombudjDnNns88aYslCyF6IY5SUw3Roz6xShcEIQ==}
     engines: {node: '>=12'}
@@ -126,12 +118,11 @@ packages:
     resolution: {integrity: sha512-0M2XxkZLx/mi3t8NVwIm1g8nHoEmM9p9UBl/G9k4+hm0kBgOVdMV/B3CY5dQ8qG8qc80NN4gDV4HQv6FTJ5q7A==}
     dev: false
 
-  /js-yaml/3.14.0:
-    resolution: {integrity: sha512-/4IbIeHcD9VMHFqDR/gQ7EdZdLimOvW2DdcxFjdyyZ9NsbS+ccrXqVWDtab/lRl5AlUqmpBx8EhPaWR+OtY17A==}
+  /js-yaml/4.1.0:
+    resolution: {integrity: sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==}
     hasBin: true
     dependencies:
-      argparse: 1.0.10
-      esprima: 4.0.1
+      argparse: 2.0.1
     dev: false
 
   /jsonfile/4.0.0:
@@ -164,10 +155,6 @@ packages:
       tslib: 1.13.0
     dev: false
 
-  /sprintf-js/1.0.3:
-    resolution: {integrity: sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw=}
-    dev: false
-
   /tslib/1.13.0:
     resolution: {integrity: sha512-i/6DQjL8Xf3be4K/E6Wgpekn5Qasl1usyw++dAA35Ue5orEn65VIxOA+YvNNl9HV3qv70T7CNwjODHZrLwvd1Q==}
     dev: false
diff --git a/tools/pkgcfg/package.json b/tools/pkgcfg/package.json
index b99e6c44..74902d26 100644
--- a/tools/pkgcfg/package.json
+++ b/tools/pkgcfg/package.json
@@ -3,8 +3,8 @@
   "version": "0.0.0",
   "private": true,
   "dependencies": {
-    "js-yaml": "^3.14.0",
+    "js-yaml": "^4.0.0",
     "@tools/places": "../places",
-    "@types/js-yaml": "^3.12.5"
+    "@types/js-yaml": "^4.0.0"
   }
 }
diff --git a/tools/pkgcfg/pnpm-lock.yaml b/tools/pkgcfg/pnpm-lock.yaml
index 987bb13c..5ab1f500 100644
--- a/tools/pkgcfg/pnpm-lock.yaml
+++ b/tools/pkgcfg/pnpm-lock.yaml
@@ -2,40 +2,27 @@ lockfileVersion: 5.3
 
 specifiers:
   '@tools/places': ../places
-  '@types/js-yaml': ^3.12.5
-  js-yaml: ^3.14.0
+  '@types/js-yaml': ^4.0.0
+  js-yaml: ^4.0.0
 
 dependencies:
   '@tools/places': link:../places
-  '@types/js-yaml': 3.12.5
-  js-yaml: 3.14.0
+  '@types/js-yaml': 4.0.5
+  js-yaml: 4.1.0
 
 packages:
 
-  /@types/js-yaml/3.12.5:
-    resolution: {integrity: sha512-JCcp6J0GV66Y4ZMDAQCXot4xprYB+Zfd3meK9+INSJeVZwJmHAW30BBEEkPzXswMXuiyReUGOP3GxrADc9wPww==}
+  /@types/js-yaml/4.0.5:
+    resolution: {integrity: sha512-FhpRzf927MNQdRZP0J5DLIdTXhjLYzeUTmLAu69mnVksLH9CJY3IuSeEgbKUki7GQZm0WqDkGzyxju2EZGD2wA==}
     dev: false
 
-  /argparse/1.0.10:
-    resolution: {integrity: sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==}
-    dependencies:
-      sprintf-js: 1.0.3
-    dev: false
-
-  /esprima/4.0.1:
-    resolution: {integrity: sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==}
-    engines: {node: '>=4'}
-    hasBin: true
+  /argparse/2.0.1:
+    resolution: {integrity: sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==}
     dev: false
 
-  /js-yaml/3.14.0:
-    resolution: {integrity: sha512-/4IbIeHcD9VMHFqDR/gQ7EdZdLimOvW2DdcxFjdyyZ9NsbS+ccrXqVWDtab/lRl5AlUqmpBx8EhPaWR+OtY17A==}
+  /js-yaml/4.1.0:
+    resolution: {integrity: sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==}
     hasBin: true
     dependencies:
-      argparse: 1.0.10
-      esprima: 4.0.1
-    dev: false
-
-  /sprintf-js/1.0.3:
-    resolution: {integrity: sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw=}
+      argparse: 2.0.1
     dev: false
diff --git a/tools/test-utils/package.json b/tools/test-utils/package.json
index f1267fc1..daa83ccb 100644
--- a/tools/test-utils/package.json
+++ b/tools/test-utils/package.json
@@ -3,7 +3,7 @@
   "version": "0.0.0",
   "private": true,
   "dependencies": {
-    "js-yaml": "^3.14.0",
-    "@types/js-yaml": "^3.12.5"
+    "js-yaml": "^4.0.0",
+    "@types/js-yaml": "^4.0.0"
   }
 }
diff --git a/tools/test-utils/pnpm-lock.yaml b/tools/test-utils/pnpm-lock.yaml
index 22d4a688..5d21f92f 100644
--- a/tools/test-utils/pnpm-lock.yaml
+++ b/tools/test-utils/pnpm-lock.yaml
@@ -1,39 +1,26 @@
 lockfileVersion: 5.3
 
 specifiers:
-  '@types/js-yaml': ^3.12.5
-  js-yaml: ^3.14.0
+  '@types/js-yaml': ^4.0.0
+  js-yaml: ^4.0.0
 
 dependencies:
-  '@types/js-yaml': 3.12.5
-  js-yaml: 3.14.0
+  '@types/js-yaml': 4.0.5
+  js-yaml: 4.1.0
 
 packages:
 
-  /@types/js-yaml/3.12.5:
-    resolution: {integrity: sha512-JCcp6J0GV66Y4ZMDAQCXot4xprYB+Zfd3meK9+INSJeVZwJmHAW30BBEEkPzXswMXuiyReUGOP3GxrADc9wPww==}
+  /@types/js-yaml/4.0.5:
+    resolution: {integrity: sha512-FhpRzf927MNQdRZP0J5DLIdTXhjLYzeUTmLAu69mnVksLH9CJY3IuSeEgbKUki7GQZm0WqDkGzyxju2EZGD2wA==}
     dev: false
 
-  /argparse/1.0.10:
-    resolution: {integrity: sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==}
-    dependencies:
-      sprintf-js: 1.0.3
-    dev: false
-
-  /esprima/4.0.1:
-    resolution: {integrity: sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==}
-    engines: {node: '>=4'}
-    hasBin: true
+  /argparse/2.0.1:
+    resolution: {integrity: sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q==}
     dev: false
 
-  /js-yaml/3.14.0:
-    resolution: {integrity: sha512-/4IbIeHcD9VMHFqDR/gQ7EdZdLimOvW2DdcxFjdyyZ9NsbS+ccrXqVWDtab/lRl5AlUqmpBx8EhPaWR+OtY17A==}
+  /js-yaml/4.1.0:
+    resolution: {integrity: sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==}
     hasBin: true
     dependencies:
-      argparse: 1.0.10
-      esprima: 4.0.1
-    dev: false
-
-  /sprintf-js/1.0.3:
-    resolution: {integrity: sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw=}
+      argparse: 2.0.1
     dev: false