diff --git a/package-lock.json b/package-lock.json
index 33bf893..4e24d1e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "ot-core",
-  "version": "0.2.1",
+  "version": "0.2.3",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -40,6 +40,7 @@
       "resolved": "https://registry.npmjs.org/align-text/-/align-text-0.1.4.tgz",
       "integrity": "sha1-DNkKVhCT810KmSVsIrcGlDP60Rc=",
       "dev": true,
+      "optional": true,
       "requires": {
         "kind-of": "^3.0.2",
         "longest": "^1.0.1",
@@ -1381,12 +1382,35 @@
       "dev": true
     },
     "cross-fetch": {
-      "version": "3.0.1",
-      "resolved": "https://registry.npmjs.org/cross-fetch/-/cross-fetch-3.0.1.tgz",
-      "integrity": "sha512-qWtpgBAF8ioqBOddRD+pHhrdzm/UWOArkrlIU7c08DlNbOxo5GfUbSY2vr90ZypWf0raW+HNN1F38pi5CEOjiQ==",
+      "version": "3.1.5",
+      "resolved": "https://registry.npmjs.org/cross-fetch/-/cross-fetch-3.1.5.tgz",
+      "integrity": "sha512-lvb1SBsI0Z7GDwmuid+mU3kWVBwTVUbe7S0H52yaaAdQOXq2YktTCZdlAcNKFzE6QtRz0snpw9bNiPeOIkkQvw==",
       "requires": {
-        "node-fetch": "2.3.0",
-        "whatwg-fetch": "3.0.0"
+        "node-fetch": "2.6.7"
+      },
+      "dependencies": {
+        "node-fetch": {
+          "version": "2.6.7",
+          "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.7.tgz",
+          "integrity": "sha512-ZjMPFEfVx5j+y2yF35Kzx5sF7kDzxuDj6ziH4FFbOp87zKDZNx8yExJIb05OGF4Nlt9IHFIMBkRl41VdvcNdbQ==",
+          "requires": {
+            "whatwg-url": "^5.0.0"
+          }
+        },
+        "webidl-conversions": {
+          "version": "3.0.1",
+          "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
+          "integrity": "sha1-JFNCdeKnvGvnvIZhHMFq4KVlSHE="
+        },
+        "whatwg-url": {
+          "version": "5.0.0",
+          "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-5.0.0.tgz",
+          "integrity": "sha1-lmRU6HZUYuN2RNNib2dCzotwll0=",
+          "requires": {
+            "tr46": "~0.0.3",
+            "webidl-conversions": "^3.0.0"
+          }
+        }
       }
     },
     "cross-spawn": {
@@ -1782,7 +1806,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -1803,12 +1828,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -1823,17 +1850,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -1950,7 +1980,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -1962,6 +1993,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -1976,6 +2008,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -1983,12 +2016,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -2007,6 +2042,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2087,7 +2123,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2099,6 +2136,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2184,7 +2222,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2220,6 +2259,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -2239,6 +2279,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2282,12 +2323,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -3627,7 +3670,8 @@
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/longest/-/longest-1.0.1.tgz",
       "integrity": "sha1-MKCy2jj3N3DoKUoNIuZiXtd9AJc=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "loose-envify": {
       "version": "1.3.1",
@@ -4706,8 +4750,7 @@
     "tr46": {
       "version": "0.0.3",
       "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
-      "integrity": "sha1-gYT9NH2snNwYWZLzpmIuFLnZq2o=",
-      "dev": true
+      "integrity": "sha1-gYT9NH2snNwYWZLzpmIuFLnZq2o="
     },
     "trim-right": {
       "version": "1.0.1",
diff --git a/package.json b/package.json
index eab72c5..33b8c1e 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
     ]
   },
   "dependencies": {
-    "cross-fetch": "^3.0.1",
+    "cross-fetch": "^3.1.5",
     "lodash": "^4.17.4",
     "node-fetch": "^2.3.0",
     "tinyqueue": "^1.2.2",