diff --git a/app/scripts/migrations/048.js b/app/scripts/migrations/048.js
index 070b12673..faf4d2a0a 100644
--- a/app/scripts/migrations/048.js
+++ b/app/scripts/migrations/048.js
@@ -92,7 +92,7 @@ function transformState (state = {}) {
   const addressBook = state.AddressBookController?.addressBook || {}
   Object.keys(addressBook).forEach((networkKey) => {
     if ((/^\d+$/ui).test(networkKey)) {
-      const chainId = `0x${networkKey.toString(16)}`
+      const chainId = `0x${parseInt(networkKey, 10).toString(16)}`
       updateChainIds(addressBook[networkKey], chainId)
 
       if (addressBook[chainId]) {
diff --git a/test/unit/migrations/048-test.js b/test/unit/migrations/048-test.js
index acc80e4b1..3fab3913b 100644
--- a/test/unit/migrations/048-test.js
+++ b/test/unit/migrations/048-test.js
@@ -237,8 +237,8 @@ describe('migration #48', function () {
 
     const newStorage = await migration48.migrate(oldStorage)
     assert.deepEqual(
-      { ...oldStorage.data, ...expectedPreferencesState },
-      { ...newStorage.data, ...expectedPreferencesState },
+      { ...expectedPreferencesState, ...oldStorage.data },
+      { ...expectedPreferencesState, ...newStorage.data },
     )
   })
 
@@ -361,6 +361,12 @@ describe('migration #48', function () {
                 foo: 'bar',
               },
             },
+            '100': {
+              'address1': {
+                chainId: '100',
+                foo: 'bar',
+              },
+            },
             '0x2': {
               'address2': {
                 chainId: '0x2',
@@ -387,6 +393,12 @@ describe('migration #48', function () {
               foo: 'bar',
             },
           },
+          '0x64': {
+            'address1': {
+              chainId: '0x64',
+              foo: 'bar',
+            },
+          },
           '0x2': {
             'address2': {
               chainId: '0x2',