diff --git a/package-lock.json b/package-lock.json
index 00ff817..0a94a22 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,28 +1,46 @@
 {
   "name": "composable-functional-javascript",
   "version": "1.0.0",
-  "lockfileVersion": 1,
+  "lockfileVersion": 3,
   "requires": true,
-  "dependencies": {
-    "data.task": {
+  "packages": {
+    "": {
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "data.task": "^3.1.2",
+        "futurize": "^1.2.0",
+        "immutable": "^4.3.8",
+        "immutable-ext": "^1.1.5"
+      }
+    },
+    "node_modules/data.task": {
       "version": "3.1.2",
       "resolved": "https://registry.npmjs.org/data.task/-/data.task-3.1.2.tgz",
-      "integrity": "sha512-gGDjno8m/FS1kdMU3EmKcLaO1enFyfCV/EscvDZ4+KZDSg9xHePa2VFfWd+QO5PUp18NdCIziOpaSUE4Efw8/w=="
+      "integrity": "sha512-gGDjno8m/FS1kdMU3EmKcLaO1enFyfCV/EscvDZ4+KZDSg9xHePa2VFfWd+QO5PUp18NdCIziOpaSUE4Efw8/w==",
+      "deprecated": "This package is no longer supported. Consider switching to fp-ts"
     },
-    "futurize": {
+    "node_modules/futurize": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/futurize/-/futurize-1.2.0.tgz",
       "integrity": "sha1-bvk6uxtTLKRUlLuW+mwJAKyrxD0="
     },
-    "immutable": {
-      "version": "4.0.0-rc.12",
-      "resolved": "https://registry.npmjs.org/immutable/-/immutable-4.0.0-rc.12.tgz",
-      "integrity": "sha512-0M2XxkZLx/mi3t8NVwIm1g8nHoEmM9p9UBl/G9k4+hm0kBgOVdMV/B3CY5dQ8qG8qc80NN4gDV4HQv6FTJ5q7A=="
+    "node_modules/immutable": {
+      "version": "4.3.8",
+      "resolved": "https://registry.npmjs.org/immutable/-/immutable-4.3.8.tgz",
+      "integrity": "sha512-d/Ld9aLbKpNwyl0KiM2CT1WYvkitQ1TSvmRtkcV8FKStiDoA7Slzgjmb/1G2yhKM1p0XeNOieaTbFZmU1d3Xuw==",
+      "license": "MIT"
     },
-    "immutable-ext": {
+    "node_modules/immutable-ext": {
       "version": "1.1.5",
       "resolved": "https://registry.npmjs.org/immutable-ext/-/immutable-ext-1.1.5.tgz",
-      "integrity": "sha1-PN8noGdSfIWBe/FhoNrRNh7Vecs="
+      "integrity": "sha1-PN8noGdSfIWBe/FhoNrRNh7Vecs=",
+      "engines": {
+        "node": ">=6.2.0"
+      },
+      "peerDependencies": {
+        "immutable": "*"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index 5b22489..c7a36e3 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
   "dependencies": {
     "data.task": "^3.1.2",
     "futurize": "^1.2.0",
-    "immutable": "^4.0.0-rc.12",
+    "immutable": "^4.3.8",
     "immutable-ext": "^1.1.5"
   }
 }