diff --git a/docs/README.md b/docs/README.md
index 99e6f773..2abc79a1 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -648,11 +648,18 @@ Serve static file.
 ### mg\_http\_reply()
 
 ```c
-void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...);
+void mg_http_reply(struct mg_connection *c, int status_code, const char *headers,
+                   const char *body_fmt, ...);
 ```
 
-Send simple HTTP response using `printf()` semantic. 
-`code` is HTTP response code, `fmt` is format for the HTTP body.
+Send simple HTTP response using `printf()` semantic. This function formats
+response body according to a `body_fmt`, and automatically appends a correct
+`Content-Length` header. Extra headers could be passed via `headers`
+parameter.
+
+- `status_code` - an HTTP response code
+- `headers` - extra headers, default NULL. If not NULL, must end with `\r\n`
+- `fmt` - a format string for the HTTP body, in a printf semantics
 
 
 ### mg\_http\_header()
diff --git a/examples/esp32/main/main.c b/examples/esp32/main/main.c
index 1538d53a..277841c1 100644
--- a/examples/esp32/main/main.c
+++ b/examples/esp32/main/main.c
@@ -10,7 +10,7 @@
 // Event handler for an accepted connection
 static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_HTTP_MSG) {
-    mg_http_reply(c, 200, "Hello from ESP32!");
+    mg_http_reply(c, 200, "", "Hello from ESP32!");
   }
 }
 
diff --git a/examples/http-restful-server/main.c b/examples/http-restful-server/main.c
index 9f098d01..7ad21982 100644
--- a/examples/http-restful-server/main.c
+++ b/examples/http-restful-server/main.c
@@ -14,9 +14,9 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_HTTP_MSG) {
     struct mg_http_message *hm = (struct mg_http_message *) ev_data;
     if (mg_http_match_uri(hm, "/api/f1")) {
-      mg_http_reply(c, 200, "{\"result\": %d}\n", 123);  // Serve REST response
+      mg_http_reply(c, 200, "", "{\"result\": %d}\n", 123);  // Serve REST
     } else if (mg_http_match_uri(hm, "/api/f2/*")) {
-      mg_http_reply(c, 200, "{\"result\": \"%.*s\"}\n", (int) hm->uri.len,
+      mg_http_reply(c, 200, "", "{\"result\": \"%.*s\"}\n", (int) hm->uri.len,
                     hm->uri.ptr);
     } else {
       mg_http_serve_dir(c, ev_data, s_web_directory);  // Serve static files
diff --git a/examples/websocket-server/main.c b/examples/websocket-server/main.c
index 94adfc73..f9b76751 100644
--- a/examples/websocket-server/main.c
+++ b/examples/websocket-server/main.c
@@ -24,7 +24,7 @@ static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
       mg_ws_upgrade(c, hm);
     } else if (mg_http_match_uri(hm, "/rest")) {
       // Serve REST response
-      mg_http_reply(c, 200, "{\"result\": %d}\n", 123);
+      mg_http_reply(c, 200, "", "{\"result\": %d}\n", 123);
     } else {
       // Serve static files
       mg_http_serve_dir(c, ev_data, s_web_directory);
diff --git a/mongoose.c b/mongoose.c
index 73672160..2973b5dd 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -586,17 +586,16 @@ void mg_http_write_chunk(struct mg_connection *c, const char *buf, size_t len) {
   mg_send(c, "\r\n", 2);
 }
 
-void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...) {
+void mg_http_reply(struct mg_connection *c, int code, const char *headers,
+                   const char *fmt, ...) {
   char mem[100], *buf = mem;
   va_list ap;
   int len;
   va_start(ap, fmt);
   len = mg_vasprintf(&buf, sizeof(mem), fmt, ap);
   va_end(ap);
-  mg_printf(c,
-            "HTTP/1.1 %d OK\r\nContent-Type: text/plain\r\n"
-            "Content-Length: %d\r\n\r\n",
-            code, len);
+  mg_printf(c, "HTTP/1.1 %d OK\r\n%sContent-Length: %d\r\n\r\n", code,
+            headers == NULL ? "" : headers, len);
   mg_send(c, buf, len);
   if (buf != mem) free(buf);
 }
@@ -623,7 +622,7 @@ int mg_http_upload(struct mg_connection *c, struct mg_http_message *hm,
   mg_http_get_var(&hm->query, "offset", offset, sizeof(offset));
   mg_http_get_var(&hm->query, "name", name, sizeof(name));
   if (name[0] == '\0') {
-    mg_http_reply(c, 400, "%s", "name required");
+    mg_http_reply(c, 400, "", "%s", "name required");
     return -1;
   } else {
     FILE *fp;
@@ -632,12 +631,12 @@ int mg_http_upload(struct mg_connection *c, struct mg_http_message *hm,
     LOG(LL_DEBUG,
         ("%p %d bytes @ %d [%s]", c->fd, (int) hm->body.len, (int) oft, name));
     if ((fp = fopen(path, oft == 0 ? "wb" : "a")) == NULL) {
-      mg_http_reply(c, 400, "fopen(%s): %d", name, errno);
+      mg_http_reply(c, 400, "", "fopen(%s): %d", name, errno);
       return -2;
     } else {
       fwrite(hm->body.ptr, 1, hm->body.len, fp);
       fclose(fp);
-      mg_http_reply(c, 200, "");
+      mg_http_reply(c, 200, "", "");
       return hm->body.len;
     }
   }
@@ -730,7 +729,7 @@ void mg_http_serve_file(struct mg_connection *c, struct mg_http_message *hm,
   char etag[64];
   if (fp == NULL || stat(path, &st) != 0 ||
       mg_http_etag(etag, sizeof(etag), &st) != etag) {
-    mg_http_reply(c, 404, "%s", "Not found\n");
+    mg_http_reply(c, 404, "", "%s", "Not found\n");
   } else if (inm != NULL && mg_vcasecmp(inm, etag) == 0) {
     mg_printf(c, "HTTP/1.1 304 Not Modified\r\nContent-Length: 0\r\n\r\n");
   } else {
@@ -950,7 +949,7 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
         MG_VERSION);
     mg_http_write_chunk(c, "", 0);
   } else {
-    mg_http_reply(c, 400, "Cannot open dir");
+    mg_http_reply(c, 400, "", "Cannot open dir");
     LOG(LL_DEBUG, ("%p opendir(%s) -> %d", c->fd, dir, errno));
   }
 }
@@ -963,7 +962,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
   if (realpath(dir, root) == NULL)
     LOG(LL_DEBUG, ("realpath(%s): %d", dir, errno));
   if (!mg_is_dir(root)) {
-    mg_http_reply(c, 400, "Bad web root [%s]\n", root);
+    mg_http_reply(c, 400, "", "Bad web root [%s]\n", root);
   } else {
     // NOTE(lsm): Xilinx snprintf does not 0-terminate the detination for
     // the %.*s specifier, if the length is zero. Make sure hm->uri.len > 0
@@ -979,7 +978,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
       is_index = true;
     }
     if (strlen(real) < strlen(root) || memcmp(real, root, strlen(root)) != 0) {
-      mg_http_reply(c, 404, "Not found %.*s\n", hm->uri.len, hm->uri.ptr);
+      mg_http_reply(c, 404, "", "Not found %.*s\n", hm->uri.len, hm->uri.ptr);
     } else {
         FILE *fp = fopen(real, "r");
 #if MG_ENABLE_HTTP_DEBUG_ENDPOINT
@@ -989,7 +988,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
 #if MG_ENABLE_DIRECTORY_LISTING
         listdir(c, hm, real);
 #else
-        mg_http_reply(c, 403, "%s", "Directory listing not supported");
+        mg_http_reply(c, 403, "", "%s", "Directory listing not supported");
 #endif
       } else {
         mg_http_serve_file(c, hm, real, guess_content_type(real));
diff --git a/mongoose.h b/mongoose.h
index c8cb9720..3116c809 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -676,7 +676,8 @@ void mg_http_serve_dir(struct mg_connection *, struct mg_http_message *hm,
                        const char *path);
 void mg_http_serve_file(struct mg_connection *, struct mg_http_message *,
                         const char *, const char *mime);
-void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...);
+void mg_http_reply(struct mg_connection *, int status_code, const char *headers,
+                   const char *body_fmt, ...);
 struct mg_str *mg_http_get_header(struct mg_http_message *, const char *name);
 void mg_http_event_handler(struct mg_connection *c, int ev);
 int mg_http_get_var(const struct mg_str *, const char *name, char *, int);
diff --git a/src/http.c b/src/http.c
index 3659b649..4c10b4d0 100644
--- a/src/http.c
+++ b/src/http.c
@@ -219,17 +219,16 @@ void mg_http_write_chunk(struct mg_connection *c, const char *buf, size_t len) {
   mg_send(c, "\r\n", 2);
 }
 
-void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...) {
+void mg_http_reply(struct mg_connection *c, int code, const char *headers,
+                   const char *fmt, ...) {
   char mem[100], *buf = mem;
   va_list ap;
   int len;
   va_start(ap, fmt);
   len = mg_vasprintf(&buf, sizeof(mem), fmt, ap);
   va_end(ap);
-  mg_printf(c,
-            "HTTP/1.1 %d OK\r\nContent-Type: text/plain\r\n"
-            "Content-Length: %d\r\n\r\n",
-            code, len);
+  mg_printf(c, "HTTP/1.1 %d OK\r\n%sContent-Length: %d\r\n\r\n", code,
+            headers == NULL ? "" : headers, len);
   mg_send(c, buf, len);
   if (buf != mem) free(buf);
 }
@@ -256,7 +255,7 @@ int mg_http_upload(struct mg_connection *c, struct mg_http_message *hm,
   mg_http_get_var(&hm->query, "offset", offset, sizeof(offset));
   mg_http_get_var(&hm->query, "name", name, sizeof(name));
   if (name[0] == '\0') {
-    mg_http_reply(c, 400, "%s", "name required");
+    mg_http_reply(c, 400, "", "%s", "name required");
     return -1;
   } else {
     FILE *fp;
@@ -265,12 +264,12 @@ int mg_http_upload(struct mg_connection *c, struct mg_http_message *hm,
     LOG(LL_DEBUG,
         ("%p %d bytes @ %d [%s]", c->fd, (int) hm->body.len, (int) oft, name));
     if ((fp = fopen(path, oft == 0 ? "wb" : "a")) == NULL) {
-      mg_http_reply(c, 400, "fopen(%s): %d", name, errno);
+      mg_http_reply(c, 400, "", "fopen(%s): %d", name, errno);
       return -2;
     } else {
       fwrite(hm->body.ptr, 1, hm->body.len, fp);
       fclose(fp);
-      mg_http_reply(c, 200, "");
+      mg_http_reply(c, 200, "", "");
       return hm->body.len;
     }
   }
@@ -363,7 +362,7 @@ void mg_http_serve_file(struct mg_connection *c, struct mg_http_message *hm,
   char etag[64];
   if (fp == NULL || stat(path, &st) != 0 ||
       mg_http_etag(etag, sizeof(etag), &st) != etag) {
-    mg_http_reply(c, 404, "%s", "Not found\n");
+    mg_http_reply(c, 404, "", "%s", "Not found\n");
   } else if (inm != NULL && mg_vcasecmp(inm, etag) == 0) {
     mg_printf(c, "HTTP/1.1 304 Not Modified\r\nContent-Length: 0\r\n\r\n");
   } else {
@@ -583,7 +582,7 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
         MG_VERSION);
     mg_http_write_chunk(c, "", 0);
   } else {
-    mg_http_reply(c, 400, "Cannot open dir");
+    mg_http_reply(c, 400, "", "Cannot open dir");
     LOG(LL_DEBUG, ("%p opendir(%s) -> %d", c->fd, dir, errno));
   }
 }
@@ -596,7 +595,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
   if (realpath(dir, root) == NULL)
     LOG(LL_DEBUG, ("realpath(%s): %d", dir, errno));
   if (!mg_is_dir(root)) {
-    mg_http_reply(c, 400, "Bad web root [%s]\n", root);
+    mg_http_reply(c, 400, "", "Bad web root [%s]\n", root);
   } else {
     // NOTE(lsm): Xilinx snprintf does not 0-terminate the detination for
     // the %.*s specifier, if the length is zero. Make sure hm->uri.len > 0
@@ -612,7 +611,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
       is_index = true;
     }
     if (strlen(real) < strlen(root) || memcmp(real, root, strlen(root)) != 0) {
-      mg_http_reply(c, 404, "Not found %.*s\n", hm->uri.len, hm->uri.ptr);
+      mg_http_reply(c, 404, "", "Not found %.*s\n", hm->uri.len, hm->uri.ptr);
     } else {
         FILE *fp = fopen(real, "r");
 #if MG_ENABLE_HTTP_DEBUG_ENDPOINT
@@ -622,7 +621,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
 #if MG_ENABLE_DIRECTORY_LISTING
         listdir(c, hm, real);
 #else
-        mg_http_reply(c, 403, "%s", "Directory listing not supported");
+        mg_http_reply(c, 403, "", "%s", "Directory listing not supported");
 #endif
       } else {
         mg_http_serve_file(c, hm, real, guess_content_type(real));
diff --git a/src/http.h b/src/http.h
index 225e57b4..0496dc77 100644
--- a/src/http.h
+++ b/src/http.h
@@ -32,7 +32,8 @@ void mg_http_serve_dir(struct mg_connection *, struct mg_http_message *hm,
                        const char *path);
 void mg_http_serve_file(struct mg_connection *, struct mg_http_message *,
                         const char *, const char *mime);
-void mg_http_reply(struct mg_connection *c, int code, const char *fmt, ...);
+void mg_http_reply(struct mg_connection *, int status_code, const char *headers,
+                   const char *body_fmt, ...);
 struct mg_str *mg_http_get_header(struct mg_http_message *, const char *name);
 void mg_http_event_handler(struct mg_connection *c, int ev);
 int mg_http_get_var(const struct mg_str *, const char *name, char *, int);
diff --git a/test/unit_test.c b/test/unit_test.c
index 20e4c274..f4b56777 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -323,19 +323,19 @@ static void eh1(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
         ("[%.*s %.*s] message len %d", (int) hm->method.len, hm->method.ptr,
          (int) hm->uri.len, hm->uri.ptr, (int) hm->message.len));
     if (mg_http_match_uri(hm, "/foo/*")) {
-      mg_http_reply(c, 200, "uri: %.*s", hm->uri.len - 5, hm->uri.ptr + 5);
+      mg_http_reply(c, 200, "", "uri: %.*s", hm->uri.len - 5, hm->uri.ptr + 5);
     } else if (mg_http_match_uri(hm, "/ws")) {
       mg_ws_upgrade(c, hm);
     } else if (mg_http_match_uri(hm, "/body")) {
-      mg_http_reply(c, 200, "%.*s", (int) hm->body.len, hm->body.ptr);
+      mg_http_reply(c, 200, "", "%.*s", (int) hm->body.len, hm->body.ptr);
     } else if (mg_http_match_uri(hm, "/bar")) {
-      mg_http_reply(c, 404, "not found");
+      mg_http_reply(c, 404, "", "not found");
     } else if (mg_http_match_uri(hm, "/badroot")) {
       mg_http_serve_dir(c, hm, "/BAAADDD!");
     } else if (mg_http_match_uri(hm, "/creds")) {
       char user[100], pass[100];
       mg_http_creds(hm, user, sizeof(user), pass, sizeof(pass));
-      mg_http_reply(c, 200, "[%s]:[%s]", user, pass);
+      mg_http_reply(c, 200, "", "[%s]:[%s]", user, pass);
     } else if (mg_http_match_uri(hm, "/upload")) {
       mg_http_upload(c, hm, ".");
     } else if (mg_http_match_uri(hm, "/test/")) {
@@ -470,10 +470,10 @@ static void test_http_server(void) {
   ASSERT(cmpbody(buf, "kuku") == 0);
 
   ASSERT(fetch(&mgr, buf, url, "GET /badroot HTTP/1.0\r\n\n") == 400);
-  // LOG(LL_INFO, ("--> [%s]", buf));
 #if MG_ARCH == MG_ARCH_WIN32
   ASSERT(cmpbody(buf, "Bad web root [Z:\\BAAADDD!]\n") == 0);
 #else
+  LOG(LL_INFO, ("--> [%s]", buf));
   ASSERT(cmpbody(buf, "Bad web root [/BAAADDD!]\n") == 0);
 #endif