diff --git a/src/constants.ts b/src/constants.ts
index 2d64934..1545993 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -1,16 +1,15 @@
 export const EOL = '\r\n'
 export const EOL2X = EOL + EOL
 
-const BASIC_LATIN = '[\\u0009\\u0020-\\u007E]'
 const HTTP_METHODS = '(CONNECT|OPTIONS|TRACE|GET|HEAD|POST|PUT|PATCH|DELETE)'
-const HTTP_PROTOCOL_VERSIONS = '(HTTP)\\/(1\\.0|1\\.1|2(\\.0){0,1})'
+const HTTP_PROTOCOL_VERSIONS = '(HTTP)\\/(1\\.0|1\\.1|2(\\.0){0,1}|3(\\.0){0,1})'
 
 export const regexps = {
   quote: /"/g,
   nlStart: new RegExp(`^${EOL}`),
   nlEnd: new RegExp(`${EOL}$`),
   requestStartRow: new RegExp(`^${HTTP_METHODS}\\s\\S*\\s${HTTP_PROTOCOL_VERSIONS}$`),
-  responseStartRow: new RegExp(`^${HTTP_PROTOCOL_VERSIONS}\\s\\d{3}\\s${BASIC_LATIN}*$`),
+  responseStartRow: new RegExp(`^${HTTP_PROTOCOL_VERSIONS}\\s\\d{3}\\s[^\r\n]*$`),
   // eslint-disable-next-line no-control-regex
   quotedHeaderValue: new RegExp('^"[\\u0009\\u0020\\u0021\\u0023-\\u007E]+"$'),
   boundary: new RegExp(`(?<=boundary=)"{0,1}[A-Za-z0-9'()+_,.:=?-]+"{0,1}`),
@@ -33,7 +32,8 @@ export enum HttpProtocol {
 export enum HttpProtocolVersion {
   http10 = 'HTTP/1.0',
   http11 = 'HTTP/1.1',
-  http20 = 'HTTP/2.0',
+  http2 = 'HTTP/2',
+  http3 = 'HTTP/3',
 }
 
 export enum HttpMethod {
diff --git a/test/parsers/request.spec.ts b/test/parsers/request.spec.ts
index 17d4b16..78e5128 100644
--- a/test/parsers/request.spec.ts
+++ b/test/parsers/request.spec.ts
@@ -212,10 +212,19 @@ describe('parsers / request', () => {
       test(startRow, expected)
     })
 
-    it('should parse valid startRow when HTTP protocol is v2.0', () => {
-      const startRow = 'GET /features HTTP/2.0'
+    it('should parse valid startRow when HTTP protocol is v2', () => {
+      const startRow = 'GET /features HTTP/2'
       const expected = getExpected({
-        protocolVersion: HttpProtocolVersion.http20,
+        protocolVersion: HttpProtocolVersion.http2,
+      })
+
+      test(startRow, expected)
+    })
+
+    it('should parse valid startRow when HTTP protocol is v3', () => {
+      const startRow = 'GET /features HTTP/3'
+      const expected = getExpected({
+        protocolVersion: HttpProtocolVersion.http3,
       })
 
       test(startRow, expected)
diff --git a/test/parsers/response.spec.ts b/test/parsers/response.spec.ts
index 20732d8..3e6a8ac 100644
--- a/test/parsers/response.spec.ts
+++ b/test/parsers/response.spec.ts
@@ -124,12 +124,12 @@ describe('parsers / response', () => {
 
     it('should set instance fields when startRow has valid format (reason is not empty)', () => {
       const parser = getParserInstance()
-      parser['startRow'] = 'HTTP/1.1 201 Created'
+      parser['startRow'] = 'HTTP/3 500 Server Error'
 
       parser['_parseStartRow']()
-      expect(parser['protocolVersion']).toEqual('HTTP/1.1')
-      expect(parser['statusCode']).toEqual(201)
-      expect(parser['statusMessage']).toEqual('Created')
+      expect(parser['protocolVersion']).toEqual('HTTP/3')
+      expect(parser['statusCode']).toEqual(500)
+      expect(parser['statusMessage']).toEqual('Server Error')
     })
   })