diff --git a/cypress/integration/rendering/packet.spec.ts b/cypress/integration/rendering/packet.spec.ts
index 990ce092c..89dce609b 100644
--- a/cypress/integration/rendering/packet.spec.ts
+++ b/cypress/integration/rendering/packet.spec.ts
@@ -1,4 +1,4 @@
-import { imgSnapshotTest, renderGraph } from '../../helpers/util';
+import { imgSnapshotTest } from '../../helpers/util';
 
 describe('packet structure', () => {
   it('should render a simple packet diagram', () => {
diff --git a/docs/config/setup/modules/defaultConfig.md b/docs/config/setup/modules/defaultConfig.md
index 7a9b891c4..d3495bc0c 100644
--- a/docs/config/setup/modules/defaultConfig.md
+++ b/docs/config/setup/modules/defaultConfig.md
@@ -14,7 +14,7 @@
 
 #### Defined in
 
-[defaultConfig.ts:272](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/defaultConfig.ts#L272)
+[defaultConfig.ts:275](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/defaultConfig.ts#L275)
 
 ---
 
diff --git a/packages/mermaid/src/defaultConfig.ts b/packages/mermaid/src/defaultConfig.ts
index 343d667af..76a8152b7 100644
--- a/packages/mermaid/src/defaultConfig.ts
+++ b/packages/mermaid/src/defaultConfig.ts
@@ -259,10 +259,6 @@ const config: RequiredDeep<MermaidConfig> = {
   },
   packet: {
     ...defaultConfigJson.packet,
-    useWidth: undefined,
-    // this is false, unlike every other diagram (other than gitGraph)
-    // TODO: can we make this default to `true` instead?
-    useMaxWidth: false,
   },
 };
 
diff --git a/packages/mermaid/src/diagrams/packet/db.ts b/packages/mermaid/src/diagrams/packet/db.ts
index d766765fc..385246d7a 100644
--- a/packages/mermaid/src/diagrams/packet/db.ts
+++ b/packages/mermaid/src/diagrams/packet/db.ts
@@ -1,13 +1,9 @@
-import type { Block, PacketDB, Row } from './types.js';
+import type { Block, PacketDB, PacketData, Row } from './types.js';
 import type { PacketDiagramConfig } from '../../config.type.js';
-
 import { log } from '../../logger.js';
 import DEFAULT_CONFIG from '../../defaultConfig.js';
 import { getConfig as commonGetConfig } from '../../config.js';
-
-interface PacketData {
-  packet: Row[];
-}
+import { cleanAndMerge } from '../../utils.js';
 
 const defaultPacketData: PacketData = {
   packet: [],
@@ -17,7 +13,7 @@ let data: PacketData = structuredClone(defaultPacketData);
 export const DEFAULT_PACKET_CONFIG: Required<PacketDiagramConfig> = DEFAULT_CONFIG.packet;
 
 export const getConfig = (): Required<PacketDiagramConfig> => {
-  const config = structuredClone({
+  const config = cleanAndMerge({
     ...DEFAULT_PACKET_CONFIG,
     ...commonGetConfig().packet,
   });
@@ -61,9 +57,9 @@ export const getNextFittingBlock = (
 };
 
 export const populate = ({ blocks }: { blocks: Block[] }) => {
+  clear();
   let lastByte = -1;
   let word: Row = [];
-  data.packet = [];
   let row = 1;
   const { bitsPerRow } = getConfig();
   for (let { start, end, label } of blocks) {
@@ -97,7 +93,6 @@ export const populate = ({ blocks }: { blocks: Block[] }) => {
   if (word.length > 0) {
     data.packet.push(word);
   }
-  log.debug(data);
 };
 
 export const clear = () => {
@@ -107,4 +102,5 @@ export const clear = () => {
 export const db: PacketDB = {
   getPacket,
   getConfig,
+  clear,
 };
diff --git a/packages/mermaid/src/diagrams/packet/styles.ts b/packages/mermaid/src/diagrams/packet/styles.ts
index d6f738a13..28292a027 100644
--- a/packages/mermaid/src/diagrams/packet/styles.ts
+++ b/packages/mermaid/src/diagrams/packet/styles.ts
@@ -1,6 +1,8 @@
+import type { DiagramStylesProvider } from '../../diagram-api/types.js';
 import { log } from '../../logger.js';
+import type { PacketStyleOptions } from './types.js';
 
-export const styles = (options: any = {}) => {
+export const styles: DiagramStylesProvider = (options: { packet?: PacketStyleOptions } = {}) => {
   log.debug({ options });
   return `
 	.byte {
diff --git a/packages/mermaid/src/diagrams/packet/types.ts b/packages/mermaid/src/diagrams/packet/types.ts
index 1ec25c040..6dc92215a 100644
--- a/packages/mermaid/src/diagrams/packet/types.ts
+++ b/packages/mermaid/src/diagrams/packet/types.ts
@@ -9,4 +9,20 @@ export type Row = Required<Block>[];
 export interface PacketDB extends DiagramDB {
   getPacket: () => Row[];
   getConfig: () => Required<PacketDiagramConfig>;
+  clear: () => void;
+}
+
+export interface PacketStyleOptions {
+  byteFontSize?: string;
+  startByteColor?: string;
+  endByteColor?: string;
+  labelColor?: string;
+  labelFontSize?: string;
+  blockStrokeColor?: string;
+  blockStrokeWidth?: string;
+  blockFillColor?: string;
+}
+
+export interface PacketData {
+  packet: Row[];
 }
diff --git a/packages/parser/src/language/packet/packet.langium b/packages/parser/src/language/packet/packet.langium
index 33adf4932..6565578dd 100644
--- a/packages/parser/src/language/packet/packet.langium
+++ b/packages/parser/src/language/packet/packet.langium
@@ -2,13 +2,19 @@ grammar Packet
 import "../common/common";
 
 entry Packet:
-	"packet-beta" NEWLINE*
-  TitleAndAccessibilities?
-  (blocks+=Block)*;
+  NEWLINE*
+	"packet-beta"
+  (  
+    NEWLINE* TitleAndAccessibilities blocks+=PacketBlock*  
+    | NEWLINE+ blocks+=PacketBlock+  
+    | NEWLINE*  
+  )
+;
 
-Block:
-    start=INT ('-' end=INT)? ':' label=STRING;
+PacketBlock:
+    start=INT('-' end=INT)? ':' label=STRING NEWLINE+
+;
 
 hidden terminal WS: /\s+/;
-terminal INT returns number: /[0-9]+/;
+terminal INT returns number: /0|[1-9][0-9]*/;
 terminal STRING: /"[^"]*"|'[^']*'/;