diff --git a/package-lock.json b/package-lock.json
index b3e2cde..8d33e1c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7,75 +7,40 @@
       "hasInstallScript": true,
       "license": "SEE LICENSE FILE",
       "dependencies": {
-        "js-yaml": "^3.13.1"
+        "js-yaml": "^4.0.0"
       },
       "devDependencies": {}
     },
     "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/js-yaml": {
-      "version": "3.13.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.0.0.tgz",
+      "integrity": "sha512-pqon0s+4ScYUvX30wxQi3PogGFAlUyH0awepWvwkj4jD4v+ova3RiYw8bmA6x2rDrEaj8i/oWKoRxpVNW+Re8Q==",
       "dependencies": {
-        "argparse": "^1.0.7",
-        "esprima": "^4.0.0"
+        "argparse": "^2.0.1"
       },
       "bin": {
         "js-yaml": "bin/js-yaml.js"
       }
-    },
-    "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=="
     },
     "js-yaml": {
-      "version": "3.13.1",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.0.0.tgz",
+      "integrity": "sha512-pqon0s+4ScYUvX30wxQi3PogGFAlUyH0awepWvwkj4jD4v+ova3RiYw8bmA6x2rDrEaj8i/oWKoRxpVNW+Re8Q==",
       "requires": {
-        "argparse": "^1.0.7",
-        "esprima": "^4.0.0"
+        "argparse": "^2.0.1"
       }
-    },
-    "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/package.json b/package.json
index e72debd..d774a58 100644
--- a/package.json
+++ b/package.json
@@ -6,10 +6,11 @@
   "contributors": [],
   "main": "main.js",
   "scripts": {
+    "test": "spago test",
     "postinstall": "spago build"
   },
   "devDependencies": {},
   "dependencies": {
-    "js-yaml": "^3.13.1"
+    "js-yaml": "^4.0.0"
   }
 }
diff --git a/src/Data/YAML/Foreign/Decode.js b/src/Data/YAML/Foreign/Decode.js
index 0e62920..6009ba3 100644
--- a/src/Data/YAML/Foreign/Decode.js
+++ b/src/Data/YAML/Foreign/Decode.js
@@ -4,7 +4,7 @@ var yaml = require('js-yaml');
 
 exports.parseYAMLImpl = function(left, right, str) {
   try {
-    return right(yaml.safeLoad(str));
+    return right(yaml.load(str));
   } catch (e) {
     return left(e.toString());
   }
diff --git a/src/Data/YAML/Foreign/Encode.js b/src/Data/YAML/Foreign/Encode.js
index ff87d11..1cfcf54 100644
--- a/src/Data/YAML/Foreign/Encode.js
+++ b/src/Data/YAML/Foreign/Encode.js
@@ -14,5 +14,5 @@ exports.objToHash = function(valueToYAMLImpl, fst, snd, obj) {
 
 exports.toYAMLImpl = function(a) {
 	// noCompatMode does not support YAML 1.1
-	return yaml.safeDump(a, {noCompatMode : true});
+	return yaml.dump(a, {noCompatMode : true});
 }