diff --git a/src/llhttp/http.ts b/src/llhttp/http.ts
index e1e44d50..5dd9f631 100644
--- a/src/llhttp/http.ts
+++ b/src/llhttp/http.ts
@@ -84,6 +84,7 @@ const NODES: ReadonlyArray<string> = [
   'chunk_size_almost_done',
   'chunk_size_almost_done_lf',
   'chunk_parameters',
+  'chunk_parameters_ows',
   'chunk_data',
   'chunk_data_almost_done',
   'chunk_data_almost_done_skip',
@@ -101,6 +102,7 @@ const NODES: ReadonlyArray<string> = [
 
 interface ISpanMap {
   readonly body: source.Span;
+  readonly chunkParameters: source.Span;
   readonly headerField: source.Span;
   readonly headerValue: source.Span;
   readonly status: source.Span;
@@ -157,6 +159,7 @@ export class HTTP {
 
     this.span = {
       body: p.span(p.code.span('llhttp__on_body')),
+      chunkParameters: p.span(p.code.span('llhttp__on_chunk_parameters')),
       headerField: p.span(p.code.span('llhttp__on_header_field')),
       headerValue: p.span(p.code.span('llhttp__on_header_value')),
       status: p.span(p.code.span('llhttp__on_status')),
@@ -798,12 +801,16 @@ export class HTTP {
 
     n('chunk_size_otherwise')
       .match('\r', n('chunk_size_almost_done'))
-      .match([ ';', ' ' ], n('chunk_parameters'))
+      .match([ ';' ], n('chunk_parameters_ows'))
       .otherwise(p.error(ERROR.INVALID_CHUNK_SIZE,
         'Invalid character in chunk size'));
 
+    n('chunk_parameters_ows')
+      .match(' ', n('chunk_parameters_ows'))
+      .otherwise(span.chunkParameters.start(n('chunk_parameters')));
+
     n('chunk_parameters')
-      .match('\r', n('chunk_size_almost_done'))
+      .peek('\r', span.chunkParameters.end().skipTo(n('chunk_size_almost_done')))
       .match(HEADER_CHARS, n('chunk_parameters'))
       .otherwise(p.error(ERROR.STRICT,
         'Invalid character in chunk parameters'));
diff --git a/src/native/api.c b/src/native/api.c
index c4ce197c..d3065b36 100644
--- a/src/native/api.c
+++ b/src/native/api.c
@@ -355,6 +355,13 @@ int llhttp__on_chunk_header(llhttp_t* s, const char* p, const char* endp) {
 }
 
 
+int llhttp__on_chunk_parameters(llhttp_t* s, const char* p, const char* endp) {
+  int err;
+  SPAN_CALLBACK_MAYBE(s, on_chunk_parameters, p, endp - p);
+  return err;
+}
+
+
 int llhttp__on_chunk_complete(llhttp_t* s, const char* p, const char* endp) {
   int err;
   CALLBACK_MAYBE(s, on_chunk_complete);
diff --git a/src/native/api.h b/src/native/api.h
index 0e71d1a6..445aa9c8 100644
--- a/src/native/api.h
+++ b/src/native/api.h
@@ -38,6 +38,9 @@ struct llhttp_settings_s {
    */
   llhttp_cb      on_headers_complete;
 
+  /* Possible return values 0, -1, HPE_USER */
+  llhttp_data_cb on_chunk_parameters;
+
   /* Possible return values 0, -1, HPE_USER */
   llhttp_data_cb on_body;
 
diff --git a/test/fixtures/extra.c b/test/fixtures/extra.c
index 7528a036..7e85a36b 100644
--- a/test/fixtures/extra.c
+++ b/test/fixtures/extra.c
@@ -203,6 +203,12 @@ int llhttp__on_body(llparse_t* s, const char* p, const char* endp) {
   return llparse__print_span("body", p, endp);
 }
 
+int llhttp__on_chunk_parameters(llparse_t* s, const char* p, const char* endp) {
+  if (llparse__in_bench)
+    return 0;
+  return llparse__print_span("chunk parameters", p, endp);
+}
+
 
 int llhttp__on_chunk_header(llparse_t* s, const char* p, const char* endp) {
   if (llparse__in_bench)
diff --git a/test/request/transfer-encoding.md b/test/request/transfer-encoding.md
index 3a596b9f..e0c4ae5e 100644
--- a/test/request/transfer-encoding.md
+++ b/test/request/transfer-encoding.md
@@ -223,9 +223,11 @@ off=66 header_field complete
 off=67 len=7 span[header_value]="chunked"
 off=76 header_value complete
 off=78 headers complete method=3 v=1/1 flags=208 content_length=0
+off=81 len=40 span[chunk parameters]="ilovew3;somuchlove=aretheseparametersfor"
 off=123 chunk header len=5
 off=123 len=5 span[body]="hello"
 off=130 chunk complete
+off=133 len=14 span[chunk parameters]="blahblah; blah"
 off=149 chunk header len=6
 off=149 len=6 span[body]=" world"
 off=157 chunk complete
@@ -598,7 +600,7 @@ off=37 header_field complete
 off=38 len=7 span[header_value]="chunked"
 off=47 header_value complete
 off=49 headers complete method=4 v=1/1 flags=208 content_length=0
-off=51 error code=2 reason="Invalid character in chunk parameters"
+off=50 error code=12 reason="Invalid character in chunk size"
 ```
 
 ## Invalid OBS fold after chunked value
diff --git a/test/response/transfer-encoding.md b/test/response/transfer-encoding.md
index 6005e049..c43e3590 100644
--- a/test/response/transfer-encoding.md
+++ b/test/response/transfer-encoding.md
@@ -33,19 +33,7 @@ off=61 header_field complete
 off=62 len=7 span[header_value]="chunked"
 off=71 header_value complete
 off=73 headers complete status=200 v=1/1 flags=208 content_length=0
-off=79 chunk header len=37
-off=79 len=35 span[body]="This is the data in the first chunk"
-off=114 len=1 span[body]=cr
-off=115 len=1 span[body]=lf
-off=118 chunk complete
-off=122 chunk header len=28
-off=122 len=26 span[body]="and this is the second one"
-off=148 len=1 span[body]=cr
-off=149 len=1 span[body]=lf
-off=152 chunk complete
-off=157 chunk header len=0
-off=159 chunk complete
-off=159 message complete
+off=75 error code=12 reason="Invalid character in chunk size"
 ```
 
 ### `chunked` before other transfer-encoding