diff --git a/e2e/decoder.test.ts b/e2e/decoder.test.ts
index 00a17d5c..4c3dec5a 100644
--- a/e2e/decoder.test.ts
+++ b/e2e/decoder.test.ts
@@ -13,10 +13,10 @@ const TOKENS_ACCOUNTS =
 
 describe('decoder', () => {
   it('decode keys', async () => {
-    const [storage, key] = await decodeKey(chain.head, SYSTEM_ACCOUNT)
-    expect(storage.section).eq('system')
-    expect(storage.method).eq('account')
-    expect(key.args.map((x) => x.toHuman())).contains('25fqepuLngYL2DK9ApTejNzqPadUUZ9ALYyKWX2jyvEiuZLa')
+    const { storage, decodedKey } = await decodeKey(chain.head, SYSTEM_ACCOUNT)
+    expect(storage?.section).eq('system')
+    expect(storage?.method).eq('account')
+    expect(decodedKey?.args.map((x) => x.toHuman())).contains('25fqepuLngYL2DK9ApTejNzqPadUUZ9ALYyKWX2jyvEiuZLa')
   })
 
   it('decode key-value', async () => {
diff --git a/src/index.ts b/src/index.ts
index e60d710d..1d7c9471 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -34,7 +34,6 @@ const defaultOptions = {
   },
   block: {
     desc: 'Block hash or block number. Default to latest block',
-    string: true,
   },
   'wasm-override': {
     desc: 'Path to wasm override',
@@ -144,11 +143,15 @@ yargs(hideBin(process.argv))
         }),
     async (argv) => {
       const context = await setup(processArgv(argv))
-      const [storage, decodedKey] = await decodeKey(context.chain.head, argv.key as HexString)
-      console.log(
-        `${storage.section}.${storage.method}`,
-        decodedKey.args.map((x) => JSON.stringify(x.toHuman())).join(', ')
-      )
+      const { storage, decodedKey } = await decodeKey(context.chain.head, argv.key as HexString)
+      if (storage && decodedKey) {
+        console.log(
+          `${storage.section}.${storage.method}`,
+          decodedKey.args.map((x) => JSON.stringify(x.toHuman())).join(', ')
+        )
+      } else {
+        console.log('Unknown')
+      }
       process.exit(0)
     }
   )
diff --git a/src/utils/decoder.ts b/src/utils/decoder.ts
index d73479aa..9c37763d 100644
--- a/src/utils/decoder.ts
+++ b/src/utils/decoder.ts
@@ -5,7 +5,7 @@ import { StorageEntry } from '@polkadot/types/primitive/types'
 import { StorageKey } from '@polkadot/types'
 import { create } from 'jsondiffpatch'
 import { hexToU8a, u8aToHex } from '@polkadot/util'
-import { merge, zipObjectDeep } from 'lodash'
+import _ from 'lodash'
 
 const diffPatcher = create({ array: { detectMove: false } })
 
@@ -28,29 +28,57 @@ const getStorageEntry = async (block: Block, key: HexString) => {
   throw new Error(`Cannot find key ${key}`)
 }
 
-export const decodeKey = async (block: Block, key: HexString): Promise<[StorageEntry, StorageKey]> => {
+export const decodeKey = async (
+  block: Block,
+  key: HexString
+): Promise<{ storage?: StorageEntry; decodedKey?: StorageKey }> => {
   const meta = await block.meta
-  const storage = await getStorageEntry(block, key)
+  const storage = await getStorageEntry(block, key).catch(() => undefined)
   const decodedKey = meta.registry.createType('StorageKey', key)
-  decodedKey.setMeta(storage.meta)
-  return [storage, decodedKey]
+  if (storage) {
+    decodedKey.setMeta(storage.meta)
+    return { storage, decodedKey }
+  }
+  return {}
 }
 
 export const decodeKeyValue = async (block: Block, key: HexString, value?: HexString | null) => {
   const meta = await block.meta
-  const [entry, storageKey] = await decodeKey(block, key)
+  const { storage, decodedKey } = await decodeKey(block, key)
+
+  if (!storage || !decodedKey) {
+    return { [key]: value }
+  }
 
-  const decodedValue = meta.registry.createType(storageKey.outputType, hexToU8a(value))
+  const decodedValue = meta.registry.createType(decodedKey.outputType, hexToU8a(value))
 
-  return {
-    [entry.section]: {
-      [entry.method]:
-        storageKey.args.length > 0
-          ? {
-              ...zipObjectDeep([storageKey.args.map((x) => x.toString()).join('.')], [decodedValue.toHuman()]),
-            }
-          : decodedValue.toHuman(),
-    },
+  switch (decodedKey.args.length) {
+    case 2: {
+      return {
+        [storage.section]: {
+          [storage.method]: {
+            [decodedKey.args[0].toString()]: {
+              [decodedKey.args[1].toString()]: decodedValue.toHuman(),
+            },
+          },
+        },
+      }
+    }
+    case 1: {
+      return {
+        [storage.section]: {
+          [storage.method]: {
+            [decodedKey.args[0].toString()]: decodedValue.toHuman(),
+          },
+        },
+      }
+    }
+    default:
+      return {
+        [storage.section]: {
+          [storage.method]: decodedValue.toHuman(),
+        },
+      }
   }
 }
 
@@ -61,10 +89,8 @@ export const decodeStorageDiff = async (block: Block, diff: [HexString, HexStrin
   const oldState = {}
   const newState = {}
   for (const [key, value] of diff) {
-    // ignore keys less than 32 chars long because they're not pallet storage
-    if (key.length < 66) continue
-    merge(oldState, await decodeKeyValue(block, key as HexString, (await parent.get(key)) as any))
-    merge(newState, await decodeKeyValue(block, key as HexString, value))
+    _.merge(oldState, await decodeKeyValue(block, key as HexString, (await parent.get(key)) as any))
+    _.merge(newState, await decodeKeyValue(block, key as HexString, value))
   }
   return [oldState, newState, diffPatcher.diff(oldState, newState)]
 }
diff --git a/template/diff.html b/template/diff.html
index 3918742a..b175a518 100644
--- a/template/diff.html
+++ b/template/diff.html
@@ -61,6 +61,11 @@
 			.unchanged {
 				color: #666;
 			}
+			.delta {
+				color: #ccc;
+				font-size: 12px;
+				margin: 0 10px;
+			}
 		</style>
 		<script src="https://unpkg.com/babel-standalone@6/babel.min.js" crossorigin></script>
 		<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js" crossorigin></script>
@@ -102,6 +107,17 @@
 					);
 				}
 
+				function renderDelta(value) {
+					if (/^\d+(,\d+)*$/.test(value[1])) {
+						const oldValue = parseInt(value[0].replace(/,/g, ''))
+						const newValue = parseInt(value[1].replace(/,/g, ''))
+						if (oldValue > 0 && newValue > 0) {
+							const delta = newValue - oldValue
+							return (<span className="delta" >{delta > 0 ? '+' : ''}{delta}</span>)
+						}
+					}
+				}
+
 				if (isDelta && Array.isArray(value)) {
 					switch (value.length) {
 						case 0:
@@ -131,6 +147,7 @@
 								'diffUpdateTo',
 								stringifyAndShrink(value[1])
 							)}
+							{renderDelta(value)}
 							</span>
 						);
 						case 3:
@@ -150,7 +167,9 @@
 			};
 
 			function prepareDelta(value) {
-				if (value && value._t === 'a') {
+				if (!value) return value;
+
+				if (value._t === 'a') {
 					const res = {};
 					for (const key in value) {
 						if (key !== '_t') {
@@ -165,7 +184,7 @@
 					}
 					return res;
 				} else {
-					if (Array.isArray(value) && value.length === 3 && value[0].length > 2 && value[0].slice(0, 2) === '@@') {
+					if (Array.isArray(value) && value.length === 3 && typeof value[0] === 'string' && value[0].startsWith('@@')) {
 						const [left, right] = value[0].split("@@").filter(x => x.length > 0)
 						const items = right.split("\n").slice(1).filter(x => x.length > 0)
 						const oldValue = items.filter(x => x[0] !== '+').map(x => x.slice(1)).join('')
@@ -216,7 +235,7 @@
 							<ReactJsonTree.JSONTree
 								theme={theme}
 								invertTheme={false}
-								data={this.state.showUnchanged ? _.merge(left, delta): delta}
+								data={this.state.showUnchanged ? _.merge(_.cloneDeep(left), delta): delta}
 								valueRenderer={valueRenderer}
 								postprocessValue={prepareDelta}
 								isCustomNode={Array.isArray}