diff --git a/src/Ed25519Keypair.js b/src/Ed25519Keypair.js
index e649901..0affec4 100644
--- a/src/Ed25519Keypair.js
+++ b/src/Ed25519Keypair.js
@@ -3,7 +3,7 @@
 // Code is Apache-2.0 and docs are CC-BY-4.0
 
 import base58 from 'bs58'
-import nacl from 'tweetnacl'
+import { sign } from 'tweetnacl'
 
 /**
  * @public
@@ -14,7 +14,7 @@ import nacl from 'tweetnacl'
  * @property {string} privateKey
  */
 export default function Ed25519Keypair(seed) {
-    const keyPair = seed ? nacl.sign.keyPair.fromSeed(seed) : nacl.sign.keyPair()
+    const keyPair = seed ? sign.keyPair.fromSeed(seed) : sign.keyPair()
     this.publicKey = base58.encode(Buffer.from(keyPair.publicKey))
     // tweetnacl's generated secret key is the secret key + public key (resulting in a 64-byte buffer)
     this.privateKey = base58.encode(Buffer.from(keyPair.secretKey.slice(0, 32)))
diff --git a/src/sanitize.js b/src/sanitize.js
index 3400472..2d7029d 100644
--- a/src/sanitize.js
+++ b/src/sanitize.js
@@ -2,8 +2,8 @@
 // SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
 // Code is Apache-2.0 and docs are CC-BY-4.0
 
-import coreIncludes from 'core-js/library/fn/array/includes'
-import coreObjectEntries from 'core-js/library/fn/object/entries'
+import 'core-js/features/array/includes';
+import 'core-js/features/object/entries'; 
 
 
 /**
@@ -14,8 +14,8 @@ import coreObjectEntries from 'core-js/library/fn/object/entries'
  */
 function filterFromObject(obj, filter, { isInclusion = true } = {}) {
     if (filter && Array.isArray(filter)) {
-        return applyFilterOnObject(obj, isInclusion ? (val => coreIncludes(filter, val))
-            : (val => !coreIncludes(filter, val)))
+        return applyFilterOnObject(obj, isInclusion ? (val => filter.includes(val))
+            : (val => !filter.includes(val)))
     } else if (filter && typeof filter === 'function') {
         // Flip the filter fn's return if it's for inclusion
         return applyFilterOnObject(obj, isInclusion ? filter
@@ -36,7 +36,7 @@ function applyFilterOnObject(obj, filterFn) {
     }
 
     const filteredObj = {}
-    coreObjectEntries(obj).forEach(([key, val]) => {
+    Object.entries(obj).forEach(([key, val]) => {
         if (filterFn(val, key)) {
             filteredObj[key] = val
         }
diff --git a/src/stringify_as_query_param.js b/src/stringify_as_query_param.js
index 8045fd6..d6afd09 100644
--- a/src/stringify_as_query_param.js
+++ b/src/stringify_as_query_param.js
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
 // Code is Apache-2.0 and docs are CC-BY-4.0
 
-import coreObjectEntries from 'core-js/library/fn/object/entries'
+import 'core-js/features/object/entries'
 import decamelize from 'decamelize'
 import queryString from 'query-string'
 
@@ -38,7 +38,7 @@ export default function stringifyAsQueryParam(obj, transform = decamelize) {
         return ''
     }
 
-    const transformedKeysObj = coreObjectEntries(obj).reduce((paramsObj, [key, value]) => {
+    const transformedKeysObj = Object.entries(obj).reduce((paramsObj, [key, value]) => {
         paramsObj[transform(key)] = value
         return paramsObj
     }, {})