diff --git a/package-lock.json b/package-lock.json
index fe17946..61e286c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "fast-geotiff",
-  "version": "1.0.0-beta.2",
+  "version": "1.0.0-beta.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -789,11 +789,6 @@
         "to-fast-properties": "^2.0.0"
       }
     },
-    "@types/zen-observable": {
-      "version": "0.8.0",
-      "resolved": "https://registry.npmjs.org/@types/zen-observable/-/zen-observable-0.8.0.tgz",
-      "integrity": "sha512-te5lMAWii1uEJ4FwLjzdlbw3+n0FZNOvFXHxQDKeT0dilh7HOzdMzV2TrJVUzq8ep7J4Na8OUYPRLSQkJHAlrg=="
-    },
     "@webassemblyjs/ast": {
       "version": "1.8.5",
       "resolved": "https://registry.npmjs.org/@webassemblyjs/ast/-/ast-1.8.5.tgz",
@@ -1660,9 +1655,9 @@
       "dev": true
     },
     "core-js": {
-      "version": "3.1.4",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.1.4.tgz",
-      "integrity": "sha512-YNZN8lt82XIMLnLirj9MhKDFZHalwzzrL9YLt6eb0T5D0EDl4IQ90IGkua8mHbnxNrkj1d8hbdizMc0Qmg1WnQ=="
+      "version": "3.6.5",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-3.6.5.tgz",
+      "integrity": "sha512-vZVEEwZoIsI+vPEuoF9Iqf5H7/M3eeQqWlQnYa8FSKKePuYTf5MWnxb5SDAzCa60b3JBRS5g9b+Dq7b1y/RCrA=="
     },
     "core-js-compat": {
       "version": "3.1.4",
@@ -1898,9 +1893,9 @@
       "dev": true
     },
     "elliptic": {
-      "version": "6.5.0",
-      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.0.tgz",
-      "integrity": "sha512-eFOJTMyCYb7xtE/caJ6JJu+bhi67WCYNbkGSknu20pmM8Ke/bqOfdnZWxyoGN26JgfxTbXrsCkEw4KheCT/KGg==",
+      "version": "6.5.3",
+      "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.3.tgz",
+      "integrity": "sha512-IMqzv5wNQf+E6aHeIqATs0tOLeOTwj1QKbRcS3jBbYkl5oLAserA8yJTT7/VyHUYG91PRmPyeQDObKLPpeS4dw==",
       "dev": true,
       "requires": {
         "bn.js": "^4.4.0",
@@ -2185,9 +2180,9 @@
       "dev": true
     },
     "fast-lzw": {
-      "version": "1.0.0-beta.2",
-      "resolved": "https://registry.npmjs.org/fast-lzw/-/fast-lzw-1.0.0-beta.2.tgz",
-      "integrity": "sha512-Xh0fTQypS+AtLmGLuDVdGcAbtpHE9p+nE7rPaIoJ/vDAvXxCxQ8ktEucVxeUElFsYh2VSAvIR7cWdWdxvyxSWw==",
+      "version": "1.0.0-beta.3",
+      "resolved": "https://registry.npmjs.org/fast-lzw/-/fast-lzw-1.0.0-beta.3.tgz",
+      "integrity": "sha512-KcinRNOdOniEnwWbQ766ZdkEYN9RxP2iw1l0s2aRbt3wq+6UCoWwuX6COU31VZ6kgKjvHDH9ce4YJ1zVwi4gow==",
       "requires": {
         "core-js": "^3.1.4",
         "threads": "^1.0.0-beta.3"
@@ -3816,6 +3811,11 @@
         "isobject": "^3.0.1"
       }
     },
+    "observable-fns": {
+      "version": "0.5.1",
+      "resolved": "https://registry.npmjs.org/observable-fns/-/observable-fns-0.5.1.tgz",
+      "integrity": "sha512-wf7g4Jpo1Wt2KIqZKLGeiuLOEMqpaOZ5gJn7DmSdqXgTdxRwSdBhWegQQpPteQ2gZvzCKqNNpwb853wcpA0j7A=="
+    },
     "once": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
@@ -4795,16 +4795,15 @@
       }
     },
     "threads": {
-      "version": "1.0.0-beta.3",
-      "resolved": "https://registry.npmjs.org/threads/-/threads-1.0.0-beta.3.tgz",
-      "integrity": "sha512-y12E1Vk6RKwZt50kQo0EyRHLiuMChnk/zEwssJp19FWnxHaKZVIsa5EMPffm7LSWE6qEFzamjqplnSSI4Fp1ww==",
+      "version": "1.6.3",
+      "resolved": "https://registry.npmjs.org/threads/-/threads-1.6.3.tgz",
+      "integrity": "sha512-tKwFIWRgfAT85KGkrpDt2jWPO8IVH0sLNfB/pXad/VW9eUIY2Zlz+QyeizypXhPHv9IHfqRzvk2t3mPw+imhWw==",
       "requires": {
-        "@types/zen-observable": "^0.8.0",
         "callsites": "^3.1.0",
         "debug": "^4.1.1",
         "is-observable": "^1.1.0",
-        "tiny-worker": ">= 2",
-        "zen-observable": "^0.8.14"
+        "observable-fns": "^0.5.1",
+        "tiny-worker": ">= 2"
       }
     },
     "through2": {
@@ -4827,12 +4826,12 @@
       }
     },
     "tiny-worker": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/tiny-worker/-/tiny-worker-2.2.0.tgz",
-      "integrity": "sha512-/DnTni0fPjjOlqA6BNcUo6pxyfbViJZ7vxwA+RZ+gF0dBevxp0sropQFVZ4NS5PRgQ8J7EBu8zMJYKwoNo5aWg==",
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/tiny-worker/-/tiny-worker-2.3.0.tgz",
+      "integrity": "sha512-pJ70wq5EAqTAEl9IkGzA+fN0836rycEuz2Cn6yeZ6FRzlVS5IDOkFHpIoEsksPRQV34GDqXm65+OlnZqUSyK2g==",
       "optional": true,
       "requires": {
-        "esm": "^3.2.22"
+        "esm": "^3.2.25"
       }
     },
     "to-arraybuffer": {
@@ -5274,11 +5273,6 @@
         "camelcase": "^5.0.0",
         "decamelize": "^1.2.0"
       }
-    },
-    "zen-observable": {
-      "version": "0.8.14",
-      "resolved": "https://registry.npmjs.org/zen-observable/-/zen-observable-0.8.14.tgz",
-      "integrity": "sha512-kQz39uonEjEESwh+qCi83kcC3rZJGh4mrZW7xjkSQYXkq//JZHTtKo+6yuVloTgMtzsIWOJrjIrKvk/dqm0L5g=="
     }
   }
 }