diff --git a/package-lock.json b/package-lock.json
index 8a977699..d9c9b522 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "openseadragon",
-  "version": "2.4.1",
+  "version": "2.4.2",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1225,8 +1225,7 @@
         "esprima": {
           "version": "4.0.1",
           "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
-          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
-          "dev": true
+          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A=="
         },
         "glob-parent": {
           "version": "5.1.0",
@@ -1252,16 +1251,6 @@
             "is-extglob": "^2.1.1"
           }
         },
-        "js-yaml": {
-          "version": "3.13.1",
-          "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-          "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
-          "dev": true,
-          "requires": {
-            "argparse": "^1.0.7",
-            "esprima": "^4.0.0"
-          }
-        },
         "lodash": {
           "version": "4.17.15",
           "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.15.tgz",
@@ -2525,8 +2514,7 @@
         "esprima": {
           "version": "4.0.1",
           "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
-          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
-          "dev": true
+          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A=="
         },
         "glob": {
           "version": "7.0.6",
@@ -2554,16 +2542,6 @@
             "resolve": "~1.1.0"
           }
         },
-        "js-yaml": {
-          "version": "3.13.1",
-          "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
-          "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
-          "dev": true,
-          "requires": {
-            "argparse": "^1.0.7",
-            "esprima": "^4.0.0"
-          }
-        },
         "resolve": {
           "version": "1.1.7",
           "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.1.7.tgz",
@@ -3638,13 +3616,21 @@
       "dev": true
     },
     "js-yaml": {
-      "version": "3.7.0",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.7.0.tgz",
-      "integrity": "sha1-XJZ93YN6m/3KXy3oQlOr6KHAO4A=",
+      "version": "3.13.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-3.13.1.tgz",
+      "integrity": "sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==",
       "dev": true,
       "requires": {
         "argparse": "^1.0.7",
-        "esprima": "^2.6.0"
+        "esprima": "^4.0.0"
+      },
+      "dependencies": {
+        "esprima": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
+          "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
+          "dev": true
+        }
       }
     },
     "json-schema-traverse": {
@@ -3792,7 +3778,7 @@
       "dependencies": {
         "chalk": {
           "version": "1.1.3",
-          "resolved": "http://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
           "integrity": "sha1-qBFcVeSnAv5NFQq9OHKCKn4J/Jg=",
           "dev": true,
           "requires": {
@@ -4506,7 +4492,7 @@
     },
     "pretty-bytes": {
       "version": "3.0.1",
-      "resolved": "http://registry.npmjs.org/pretty-bytes/-/pretty-bytes-3.0.1.tgz",
+      "resolved": "https://registry.npmjs.org/pretty-bytes/-/pretty-bytes-3.0.1.tgz",
       "integrity": "sha1-J9AAjXeAY6C0gRuzXHnxvV1fvM8=",
       "dev": true,
       "requires": {