diff --git a/src/env-inl.h b/src/env-inl.h
index 05c7a90c52fee7..3fe57f808cfec7 100644
--- a/src/env-inl.h
+++ b/src/env-inl.h
@@ -469,6 +469,14 @@ inline void Environment::set_http_parser_buffer(char* buffer) {
   http_parser_buffer_ = buffer;
 }
 
+inline bool Environment::http_parser_buffer_in_use() const {
+  return http_parser_buffer_in_use_;
+}
+
+inline void Environment::set_http_parser_buffer_in_use(bool in_use) {
+  http_parser_buffer_in_use_ = in_use;
+}
+
 inline http2::http2_state* Environment::http2_state() const {
   return http2_state_.get();
 }
diff --git a/src/env.h b/src/env.h
index 868f3e9f212f67..4b874677935edb 100644
--- a/src/env.h
+++ b/src/env.h
@@ -646,6 +646,8 @@ class Environment {
 
   inline char* http_parser_buffer() const;
   inline void set_http_parser_buffer(char* buffer);
+  inline bool http_parser_buffer_in_use() const;
+  inline void set_http_parser_buffer_in_use(bool in_use);
 
   inline http2::http2_state* http2_state() const;
   inline void set_http2_state(std::unique_ptr<http2::http2_state> state);
@@ -828,6 +830,7 @@ class Environment {
   double* heap_space_statistics_buffer_ = nullptr;
 
   char* http_parser_buffer_;
+  bool http_parser_buffer_in_use_ = false;
   std::unique_ptr<http2::http2_state> http2_state_;
 
   // stat fields contains twice the number of entries because `fs.StatWatcher`
diff --git a/src/node_http_parser.cc b/src/node_http_parser.cc
index 207310f4068f43..8ab13e07340929 100644
--- a/src/node_http_parser.cc
+++ b/src/node_http_parser.cc
@@ -525,6 +525,14 @@ class Parser : public AsyncWrap, public StreamListener {
   static const size_t kAllocBufferSize = 64 * 1024;
 
   uv_buf_t OnStreamAlloc(size_t suggested_size) override {
+    // For most types of streams, OnStreamRead will be immediately after
+    // OnStreamAlloc, and will consume all data, so using a static buffer for
+    // reading is more efficient. For other streams, just use the default
+    // allocator, which uses Malloc().
+    if (env()->http_parser_buffer_in_use())
+      return StreamListener::OnStreamAlloc(suggested_size);
+    env()->set_http_parser_buffer_in_use(true);
+
     if (env()->http_parser_buffer() == nullptr)
       env()->set_http_parser_buffer(new char[kAllocBufferSize]);
 
@@ -534,6 +542,15 @@ class Parser : public AsyncWrap, public StreamListener {
 
   void OnStreamRead(ssize_t nread, const uv_buf_t& buf) override {
     HandleScope scope(env()->isolate());
+    // Once we’re done here, either indicate that the HTTP parser buffer
+    // is free for re-use, or free() the data if it didn’t come from there
+    // in the first place.
+    OnScopeLeave on_scope_leave([&]() {
+      if (buf.base == env()->http_parser_buffer())
+        env()->set_http_parser_buffer_in_use(false);
+      else
+        free(buf.base);
+    });
 
     if (nread < 0) {
       PassReadErrorToPreviousListener(nread);
diff --git a/src/util.h b/src/util.h
index c822390ec56f8b..e871fc63a5c46a 100644
--- a/src/util.h
+++ b/src/util.h
@@ -436,6 +436,14 @@ class BufferValue : public MaybeStackBuffer<char> {
 template <typename T> inline void USE(T&&) {}
 }  // namespace node
 
+// Run a function when exiting the current scope.
+struct OnScopeLeave {
+  std::function<void()> fn_;
+
+  explicit OnScopeLeave(std::function<void()> fn) : fn_(fn) {}
+  ~OnScopeLeave() { fn_(); }
+};
+
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #endif  // SRC_UTIL_H_