diff --git a/http_parser.c b/http_parser.c
index 73b6d86..534473e 100644
--- a/http_parser.c
+++ b/http_parser.c
@@ -26,6 +26,7 @@
 #include <stddef.h>
 #include <ctype.h>
 #include <stdlib.h>
+#include <string.h>
 
 
 #ifndef MIN
@@ -1849,12 +1850,11 @@ const char * http_method_str (enum http_method m)
 void
 http_parser_init (http_parser *parser, enum http_parser_type t)
 {
+  void *data = parser->data; /* preserve application data */
+  memset(parser, 0, sizeof(*parser));
+  parser->data = data;
   parser->type = t;
   parser->state = (t == HTTP_REQUEST ? s_start_req : (t == HTTP_RESPONSE ? s_start_res : s_start_req_or_res));
-  parser->nread = 0;
-  parser->upgrade = 0;
-  parser->flags = 0;
-  parser->method = 0;
   parser->http_errno = HPE_OK;
 }
 
diff --git a/test.c b/test.c
index 7738fe5..ad5b008 100644
--- a/test.c
+++ b/test.c
@@ -1835,6 +1835,18 @@ print_error (const char *raw, size_t error_location)
   fprintf(stderr, "^\n\nerror location: %u\n", (unsigned int)error_location);
 }
 
+void
+test_preserve_data (void)
+{
+  char my_data[] = "application-specific data";
+  http_parser parser;
+  parser.data = my_data;
+  http_parser_init(&parser, HTTP_REQUEST);
+  if (parser.data != my_data) {
+    printf("\n*** parser.data not preserved accross http_parser_init ***\n\n");
+    exit(1);
+  }
+}
 
 void
 test_message (const struct message *message)
@@ -2295,6 +2307,9 @@ main (void)
   for (request_count = 0; requests[request_count].name; request_count++);
   for (response_count = 0; responses[response_count].name; response_count++);
 
+  //// API
+  test_preserve_data();
+
   //// OVERFLOW CONDITIONS
 
   test_header_overflow_error(HTTP_REQUEST);