diff --git a/js/package-lock.json b/js/package-lock.json
index 2110892..22115ac 100644
--- a/js/package-lock.json
+++ b/js/package-lock.json
@@ -9,29 +9,14 @@
       "version": "1.0.0",
       "license": "MIT",
       "dependencies": {
-        "js-yaml": "^3.7.0",
+        "js-yaml": "^4.1.1",
         "rivescript": "^1.17.0"
       }
     },
     "node_modules/argparse": {
-      "version": "1.0.10",
-      "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.10.tgz",
-      "integrity": "sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==",
-      "dependencies": {
-        "sprintf-js": "~1.0.2"
-      }
-    },
-    "node_modules/esprima": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
-      "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
-      "bin": {
-        "esparse": "bin/esparse.js",
-        "esvalidate": "bin/esvalidate.js"
-      },
-      "engines": {
-        "node": ">=4"
-      }
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
+      "integrity": "sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q=="
     },
     "node_modules/fs-readdir-recursive": {
       "version": "1.1.0",
@@ -39,12 +24,11 @@
       "integrity": "sha512-GNanXlVr2pf02+sPN40XN8HG+ePaNcvM0q5mZBd668Obwb0yD5GiUbZOFgwn8kGMY6I3mdyDJzieUy3PTYyTRA=="
     },
     "node_modules/js-yaml": {
-      "version": "3.14.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.14.1.tgz",
-      "integrity": "sha512-okMH7OXXJ7YrN9Ok3/SXrnu4iX9yOk+25nqX4imS2npuvTYDmo/QEZoqwZkYaIDk3jVvBOTOIEgEhaLOynBS9g==",
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.1.tgz",
+      "integrity": "sha512-qQKT4zQxXl8lLwBtHMWwaTcGfFOZviOJet3Oy/xmGk2gZH677CJM9EvtfdSkgWcATZhj/55JZ0rmy3myCT5lsA==",
       "dependencies": {
-        "argparse": "^1.0.7",
-        "esprima": "^4.0.0"
+        "argparse": "^2.0.1"
       },
       "bin": {
         "js-yaml": "bin/js-yaml.js"
@@ -66,26 +50,13 @@
       "engines": {
         "node": "0.12.* || 4.* || 6.* || >= 7.*"
       }
-    },
-    "node_modules/sprintf-js": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz",
-      "integrity": "sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw="
     }
   },
   "dependencies": {
     "argparse": {
-      "version": "1.0.10",
-      "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.10.tgz",
-      "integrity": "sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==",
-      "requires": {
-        "sprintf-js": "~1.0.2"
-      }
-    },
-    "esprima": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
-      "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A=="
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/argparse/-/argparse-2.0.1.tgz",
+      "integrity": "sha512-8+9WqebbFzpX9OR+Wa6O29asIogeRMzcGtAINdpMHHyAg10f05aSFVBbcEqGf/PXw1EjAZ+q2/bEBg3DvurK3Q=="
     },
     "fs-readdir-recursive": {
       "version": "1.1.0",
@@ -93,12 +64,11 @@
       "integrity": "sha512-GNanXlVr2pf02+sPN40XN8HG+ePaNcvM0q5mZBd668Obwb0yD5GiUbZOFgwn8kGMY6I3mdyDJzieUy3PTYyTRA=="
     },
     "js-yaml": {
-      "version": "3.14.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.14.1.tgz",
-      "integrity": "sha512-okMH7OXXJ7YrN9Ok3/SXrnu4iX9yOk+25nqX4imS2npuvTYDmo/QEZoqwZkYaIDk3jVvBOTOIEgEhaLOynBS9g==",
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.1.tgz",
+      "integrity": "sha512-qQKT4zQxXl8lLwBtHMWwaTcGfFOZviOJet3Oy/xmGk2gZH677CJM9EvtfdSkgWcATZhj/55JZ0rmy3myCT5lsA==",
       "requires": {
-        "argparse": "^1.0.7",
-        "esprima": "^4.0.0"
+        "argparse": "^2.0.1"
       }
     },
     "rivescript": {
@@ -114,11 +84,6 @@
       "version": "3.6.2",
       "resolved": "https://registry.npmjs.org/rsvp/-/rsvp-3.6.2.tgz",
       "integrity": "sha512-OfWGQTb9vnwRjwtA2QwpG2ICclHC3pgXZO5xt8H2EfgDquO0qVdSb5T88L4qJVAEugbS56pAuV4XZM58UX8ulw=="
-    },
-    "sprintf-js": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz",
-      "integrity": "sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw="
     }
   }
 }
diff --git a/js/package.json b/js/package.json
index dccec32..21b4260 100644
--- a/js/package.json
+++ b/js/package.json
@@ -17,7 +17,7 @@
   },
   "homepage": "https://github.com/aichaos/rsts#readme",
   "dependencies": {
-    "js-yaml": "^3.7.0",
+    "js-yaml": "^4.1.1",
     "rivescript": "^1.17.0"
   }
 }