diff --git a/src/arm64/dom_parser_implementation.cpp b/src/arm64/dom_parser_implementation.cpp
index b3a548da8..60586bfb0 100644
--- a/src/arm64/dom_parser_implementation.cpp
+++ b/src/arm64/dom_parser_implementation.cpp
@@ -84,8 +84,10 @@ WARN_UNUSED error_code implementation::minify(const uint8_t *buf, size_t len, ui
 
 #include "generic/stage1/utf8_lookup2_algorithm.h"
 #include "generic/stage1/json_structural_indexer.h"
-WARN_UNUSED error_code implementation::stage1(const uint8_t *buf, size_t len, parser &parser, bool streaming) const noexcept {
-  return arm64::stage1::json_structural_indexer::index<64>(buf, len, parser, streaming);
+WARN_UNUSED error_code implementation::stage1(const uint8_t *_buf, size_t _len, parser &parser, bool streaming) const noexcept {
+  this->buf = _buf;
+  this->len = _len;
+  return arm64::stage1::json_structural_indexer::index<64>(_buf, _len, parser, streaming);
 }
 
 } // namespace arm64
diff --git a/src/arm64/dom_parser_implementation.h b/src/arm64/dom_parser_implementation.h
index be752fb06..f6e211596 100644
--- a/src/arm64/dom_parser_implementation.h
+++ b/src/arm64/dom_parser_implementation.h
@@ -9,7 +9,12 @@ namespace arm64 {
 
 class dom_parser_implementation final : public internal::dom_parser_implementation {
 public:
+  const uint8_t *buf{}; // Buffer passed to stage 1
+  size_t len{0}; // Length passed to stage 1
+
   really_inline dom_parser_implementation();
+  dom_parser_implementation(const dom_parser_implementation &) = delete;
+  dom_parser_implementation &operator =(const dom_parser_implementation &) = delete;
   
   WARN_UNUSED virtual error_code parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept;
   WARN_UNUSED virtual error_code stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept;
@@ -30,10 +35,10 @@ WARN_UNUSED error_code dom_parser_implementation::set_max_depth(size_t) noexcept
   return SUCCESS;
 }
 
-WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept {
-  error_code code = stage1(buf, len, parser, false);
+WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *_buf, size_t _len, dom::parser &parser) noexcept {
+  error_code code = stage1(_buf, _len, parser, false);
   if (!code) {
-    code = stage2(buf, len, parser);
+    code = stage2(_buf, _len, parser);
   }
   return code;
 }
diff --git a/src/fallback/dom_parser_implementation.cpp b/src/fallback/dom_parser_implementation.cpp
index 01ac68314..f24b2aae2 100644
--- a/src/fallback/dom_parser_implementation.cpp
+++ b/src/fallback/dom_parser_implementation.cpp
@@ -145,11 +145,13 @@ private:
 } // namespace stage1
 
 
-WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept {
-  if (unlikely(len > parser.capacity())) {
+WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *_buf, size_t _len, dom::parser &parser, bool streaming) noexcept {
+  if (unlikely(_len > parser.capacity())) {
     return CAPACITY;
   }
-  stage1::structural_scanner scanner(buf, uint32_t(len), parser, streaming);
+  this->buf = _buf;
+  this->len = _len;
+  stage1::structural_scanner scanner(_buf, uint32_t(_len), parser, streaming);
   return scanner.scan();
 }
 
diff --git a/src/fallback/dom_parser_implementation.h b/src/fallback/dom_parser_implementation.h
index 4057a1186..5185a7f0a 100644
--- a/src/fallback/dom_parser_implementation.h
+++ b/src/fallback/dom_parser_implementation.h
@@ -9,7 +9,12 @@ namespace fallback {
 
 class dom_parser_implementation final : public internal::dom_parser_implementation {
 public:
+  const uint8_t *buf{}; // Buffer passed to stage 1
+  size_t len{0}; // Length passed to stage 1
+
   really_inline dom_parser_implementation();
+  dom_parser_implementation(const dom_parser_implementation &) = delete;
+  dom_parser_implementation &operator =(const dom_parser_implementation &) = delete;
   
   WARN_UNUSED virtual error_code parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept;
   WARN_UNUSED virtual error_code stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept;
@@ -30,10 +35,10 @@ WARN_UNUSED error_code dom_parser_implementation::set_max_depth(size_t) noexcept
   return SUCCESS;
 }
 
-WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept {
-  error_code code = stage1(buf, len, parser, false);
+WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *_buf, size_t _len, dom::parser &parser) noexcept {
+  error_code code = stage1(_buf, _len, parser, false);
   if (!code) {
-    code = stage2(buf, len, parser);
+    code = stage2(_buf, _len, parser);
   }
   return code;
 }
diff --git a/src/generic/stage2/streaming_structural_parser.h b/src/generic/stage2/streaming_structural_parser.h
index 3aa6ff087..031565dff 100755
--- a/src/generic/stage2/streaming_structural_parser.h
+++ b/src/generic/stage2/streaming_structural_parser.h
@@ -4,7 +4,7 @@ struct streaming_structural_parser: structural_parser {
   really_inline streaming_structural_parser(const uint8_t *buf, size_t len, dom::parser &_doc_parser, uint32_t next_structural) : structural_parser(buf, len, _doc_parser, next_structural) {}
 
   // override to add streaming
-  WARN_UNUSED really_inline error_code start(UNUSED size_t len, ret_address finish_parser) {
+  WARN_UNUSED really_inline error_code start(ret_address finish_parser) {
     log_start();
     init(); // sets is_valid to false
     // Capacity ain't no thang for streaming, so we don't check it.
@@ -44,10 +44,11 @@ struct streaming_structural_parser: structural_parser {
  * The JSON is parsed to a tape, see the accompanying tape.md file
  * for documentation.
  ***********/
-WARN_UNUSED error_code dom_parser_implementation::stage2(const uint8_t *buf, size_t len, dom::parser &doc_parser, size_t &next_json) noexcept {
+WARN_UNUSED error_code dom_parser_implementation::stage2(const uint8_t *_buf, size_t _len, dom::parser &doc_parser, size_t &next_json) noexcept {
   static constexpr stage2::unified_machine_addresses addresses = INIT_ADDRESSES();
-  stage2::streaming_structural_parser parser(buf, len, doc_parser, uint32_t(next_json));
-  error_code result = parser.start(len, addresses.finish);
+
+  stage2::streaming_structural_parser parser(_buf, _len, doc_parser, uint32_t(next_json));
+  error_code result = parser.start(addresses.finish);
   if (result) { return result; }
   //
   // Read first value
diff --git a/src/generic/stage2/structural_parser.h b/src/generic/stage2/structural_parser.h
index 18edfff2f..bc0d8c331 100644
--- a/src/generic/stage2/structural_parser.h
+++ b/src/generic/stage2/structural_parser.h
@@ -398,10 +398,10 @@ struct structural_parser {
  * The JSON is parsed to a tape, see the accompanying tape.md file
  * for documentation.
  ***********/
-WARN_UNUSED error_code dom_parser_implementation::stage2(const uint8_t *buf, size_t len, dom::parser &doc_parser) noexcept {
+WARN_UNUSED error_code dom_parser_implementation::stage2(const uint8_t *_buf, size_t _len, dom::parser &doc_parser) noexcept {
   static constexpr stage2::unified_machine_addresses addresses = INIT_ADDRESSES();
-  stage2::structural_parser parser(buf, len, doc_parser);
-  error_code result = parser.start(len, addresses.finish);
+  stage2::structural_parser parser(_buf, _len, doc_parser);
+  error_code result = parser.start(_len, addresses.finish);
   if (result) { return result; }
 
   //
diff --git a/src/haswell/dom_parser_implementation.cpp b/src/haswell/dom_parser_implementation.cpp
index ff19f288c..8159f67fc 100644
--- a/src/haswell/dom_parser_implementation.cpp
+++ b/src/haswell/dom_parser_implementation.cpp
@@ -72,8 +72,10 @@ WARN_UNUSED error_code implementation::minify(const uint8_t *buf, size_t len, ui
 
 #include "generic/stage1/utf8_lookup2_algorithm.h"
 #include "generic/stage1/json_structural_indexer.h"
-WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept {
-  return haswell::stage1::json_structural_indexer::index<128>(buf, len, parser, streaming);
+WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *_buf, size_t _len, dom::parser &parser, bool streaming) noexcept {
+  this->buf = _buf;
+  this->len = _len;
+  return haswell::stage1::json_structural_indexer::index<128>(_buf, _len, parser, streaming);
 }
 
 } // namespace haswell
diff --git a/src/haswell/dom_parser_implementation.h b/src/haswell/dom_parser_implementation.h
index 8a08649c1..7d974dfda 100644
--- a/src/haswell/dom_parser_implementation.h
+++ b/src/haswell/dom_parser_implementation.h
@@ -9,7 +9,12 @@ namespace haswell {
 
 class dom_parser_implementation final : public internal::dom_parser_implementation {
 public:
+  const uint8_t *buf{}; // Buffer passed to stage 1
+  size_t len{0}; // Length passed to stage 1
+
   really_inline dom_parser_implementation();
+  dom_parser_implementation(const dom_parser_implementation &) = delete;
+  dom_parser_implementation &operator =(const dom_parser_implementation &) = delete;
   
   WARN_UNUSED virtual error_code parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept;
   WARN_UNUSED virtual error_code stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept;
@@ -30,10 +35,10 @@ WARN_UNUSED error_code dom_parser_implementation::set_max_depth(size_t) noexcept
   return SUCCESS;
 }
 
-WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept {
-  error_code code = stage1(buf, len, parser, false);
+WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *_buf, size_t _len, dom::parser &parser) noexcept {
+  error_code code = stage1(_buf, _len, parser, false);
   if (!code) {
-    code = stage2(buf, len, parser);
+    code = stage2(_buf, _len, parser);
   }
   return code;
 }
diff --git a/src/westmere/dom_parser_implementation.cpp b/src/westmere/dom_parser_implementation.cpp
index 2f5f84f32..1f145e498 100644
--- a/src/westmere/dom_parser_implementation.cpp
+++ b/src/westmere/dom_parser_implementation.cpp
@@ -73,8 +73,10 @@ WARN_UNUSED error_code implementation::minify(const uint8_t *buf, size_t len, ui
 
 #include "generic/stage1/utf8_lookup2_algorithm.h"
 #include "generic/stage1/json_structural_indexer.h"
-WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *buf, size_t len, parser &parser, bool streaming) noexcept {
-  return westmere::stage1::json_structural_indexer::index<64>(buf, len, parser, streaming);
+WARN_UNUSED error_code dom_parser_implementation::stage1(const uint8_t *_buf, size_t _len, parser &parser, bool streaming) noexcept {
+  this->buf = _buf;
+  this->len = _len;
+  return westmere::stage1::json_structural_indexer::index<64>(_buf, _len, parser, streaming);
 }
 
 } // namespace westmere
diff --git a/src/westmere/dom_parser_implementation.h b/src/westmere/dom_parser_implementation.h
index 23b88ecef..0bfe71385 100644
--- a/src/westmere/dom_parser_implementation.h
+++ b/src/westmere/dom_parser_implementation.h
@@ -9,7 +9,12 @@ namespace westmere {
 
 class dom_parser_implementation final : public internal::dom_parser_implementation {
 public:
+  const uint8_t *buf{}; // Buffer passed to stage 1
+  size_t len{0}; // Length passed to stage 1
+
   really_inline dom_parser_implementation();
+  dom_parser_implementation(const dom_parser_implementation &) = delete;
+  dom_parser_implementation &operator =(const dom_parser_implementation &) = delete;
   
   WARN_UNUSED virtual error_code parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept;
   WARN_UNUSED virtual error_code stage1(const uint8_t *buf, size_t len, dom::parser &parser, bool streaming) noexcept;
@@ -30,10 +35,10 @@ WARN_UNUSED error_code dom_parser_implementation::set_max_depth(size_t) noexcept
   return SUCCESS;
 }
 
-WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *buf, size_t len, dom::parser &parser) noexcept {
-  error_code code = stage1(buf, len, parser, false);
+WARN_UNUSED error_code dom_parser_implementation::parse(const uint8_t *_buf, size_t _len, dom::parser &parser) noexcept {
+  error_code code = stage1(_buf, _len, parser, false);
   if (!code) {
-    code = stage2(buf, len, parser);
+    code = stage2(_buf, _len, parser);
   }
   return code;
 }