diff --git a/docs/README.md b/docs/README.md
index e88d114c..f9bab9ae 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -686,8 +686,9 @@ Write a chunk of data in chunked encoding format.
 
 ```c
 struct mg_http_serve_opts {
-  const char *root_dir;     // Web root directory, must be non-NULL
-  const char *ssi_pattern;  // SSI filename pattern, e.g. #.shtml
+  const char *root_dir;       // Web root directory, must be non-NULL
+  const char *ssi_pattern;    // SSI filename pattern, e.g. #.shtml
+  const char *extra_headers;  // Extra HTTP headers to add in responses
 };
 void mg_http_serve_dir(struct mg_connection *, struct mg_http_message *hm,
                        const struct mg_http_serve_opts *opts);
diff --git a/examples/http-server/main.c b/examples/http-server/main.c
index 00811ea6..a311e063 100644
--- a/examples/http-server/main.c
+++ b/examples/http-server/main.c
@@ -11,7 +11,7 @@ static const char *s_ssi_pattern = "#.shtml";
 
 static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
   if (ev == MG_EV_HTTP_MSG) {
-    struct mg_http_serve_opts opts = {s_root_dir, s_ssi_pattern};
+    struct mg_http_serve_opts opts = {s_root_dir, s_ssi_pattern, NULL};
     mg_http_serve_dir(c, ev_data, &opts);
   }
   (void) fn_data;
diff --git a/mongoose.c b/mongoose.c
index 195fed9b..0f48089a 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -970,7 +970,7 @@ static void printdirentry(struct mg_connection *c, const char *name,
 }
 
 static void listdir(struct mg_connection *c, struct mg_http_message *hm,
-                    char *dir) {
+                    struct mg_http_serve_opts *opts, char *dir) {
   char path[MG_PATH_MAX], *p = &dir[strlen(dir) - 1], tmp[10];
   struct dirent *dp;
   DIR *dirp;
@@ -1001,10 +1001,12 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
   while (p > dir && *p != '/') *p-- = '\0';
   if ((dirp = (opendir(dir))) != NULL) {
     size_t off, n;
-    mg_printf(c, "%s\r\n",
+    mg_printf(c,
               "HTTP/1.1 200 OK\r\n"
               "Content-Type: text/html; charset=utf-8\r\n"
-              "Content-Length:         \r\n");
+              "%s"
+              "Content-Length:         \r\n\r\n",
+              opts->extra_headers == NULL ? "" : opts->extra_headers);
     off = c->send.len;  // Start of body
     mg_printf(c,
               "<!DOCTYPE html><html><head><title>Index of %.*s</title>%s%s"
@@ -1099,7 +1101,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
 #endif
       if (is_index && fp == NULL) {
 #if MG_ENABLE_DIRECTORY_LISTING
-        listdir(c, hm, t2);
+        listdir(c, hm, opts, t2);
 #else
         mg_http_reply(c, 403, "", "%s", "Directory listing not supported");
 #endif
@@ -1111,7 +1113,8 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
         mg_http_serve_ssi(c, t1, t2);
 #endif
       } else {
-        mg_http_serve_file(c, hm, t2, guess_content_type(t2), NULL);
+        mg_http_serve_file(c, hm, t2, guess_content_type(t2),
+                           opts->extra_headers);
       }
       if (fp != NULL) fclose(fp);
     }
diff --git a/mongoose.h b/mongoose.h
index 12f7b2b3..ac3618d6 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -688,8 +688,9 @@ struct mg_http_message {
 
 // Parameter for mg_http_serve_dir()
 struct mg_http_serve_opts {
-  const char *root_dir;     // Web root directory, must be non-NULL
-  const char *ssi_pattern;  // SSI filename pattern, e.g. #.shtml
+  const char *root_dir;       // Web root directory, must be non-NULL
+  const char *ssi_pattern;    // SSI filename pattern, e.g. #.shtml
+  const char *extra_headers;  // Extra HTTP headers to add in responses
 };
 
 int mg_http_parse(const char *s, size_t len, struct mg_http_message *);
diff --git a/src/http.c b/src/http.c
index 78b834b9..8660a899 100644
--- a/src/http.c
+++ b/src/http.c
@@ -551,7 +551,7 @@ static void printdirentry(struct mg_connection *c, const char *name,
 }
 
 static void listdir(struct mg_connection *c, struct mg_http_message *hm,
-                    char *dir) {
+                    struct mg_http_serve_opts *opts, char *dir) {
   char path[MG_PATH_MAX], *p = &dir[strlen(dir) - 1], tmp[10];
   struct dirent *dp;
   DIR *dirp;
@@ -582,10 +582,12 @@ static void listdir(struct mg_connection *c, struct mg_http_message *hm,
   while (p > dir && *p != '/') *p-- = '\0';
   if ((dirp = (opendir(dir))) != NULL) {
     size_t off, n;
-    mg_printf(c, "%s\r\n",
+    mg_printf(c,
               "HTTP/1.1 200 OK\r\n"
               "Content-Type: text/html; charset=utf-8\r\n"
-              "Content-Length:         \r\n");
+              "%s"
+              "Content-Length:         \r\n\r\n",
+              opts->extra_headers == NULL ? "" : opts->extra_headers);
     off = c->send.len;  // Start of body
     mg_printf(c,
               "<!DOCTYPE html><html><head><title>Index of %.*s</title>%s%s"
@@ -680,7 +682,7 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
 #endif
       if (is_index && fp == NULL) {
 #if MG_ENABLE_DIRECTORY_LISTING
-        listdir(c, hm, t2);
+        listdir(c, hm, opts, t2);
 #else
         mg_http_reply(c, 403, "", "%s", "Directory listing not supported");
 #endif
@@ -692,7 +694,8 @@ void mg_http_serve_dir(struct mg_connection *c, struct mg_http_message *hm,
         mg_http_serve_ssi(c, t1, t2);
 #endif
       } else {
-        mg_http_serve_file(c, hm, t2, guess_content_type(t2), NULL);
+        mg_http_serve_file(c, hm, t2, guess_content_type(t2),
+                           opts->extra_headers);
       }
       if (fp != NULL) fclose(fp);
     }
diff --git a/src/http.h b/src/http.h
index 13a4ae06..6e0ccb03 100644
--- a/src/http.h
+++ b/src/http.h
@@ -23,8 +23,9 @@ struct mg_http_message {
 
 // Parameter for mg_http_serve_dir()
 struct mg_http_serve_opts {
-  const char *root_dir;     // Web root directory, must be non-NULL
-  const char *ssi_pattern;  // SSI filename pattern, e.g. #.shtml
+  const char *root_dir;       // Web root directory, must be non-NULL
+  const char *ssi_pattern;    // SSI filename pattern, e.g. #.shtml
+  const char *extra_headers;  // Extra HTTP headers to add in responses
 };
 
 int mg_http_parse(const char *s, size_t len, struct mg_http_message *);
diff --git a/test/unit_test.c b/test/unit_test.c
index ab9da266..c703679b 100644
--- a/test/unit_test.c
+++ b/test/unit_test.c
@@ -337,7 +337,7 @@ static void eh1(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
     } else if (mg_http_match_uri(hm, "/bar")) {
       mg_http_reply(c, 404, "", "not found");
     } else if (mg_http_match_uri(hm, "/badroot")) {
-      struct mg_http_serve_opts opts = {"/BAAADDD!", NULL};
+      struct mg_http_serve_opts opts = {"/BAAADDD!", NULL, NULL};
       mg_http_serve_dir(c, hm, &opts);
     } else if (mg_http_match_uri(hm, "/creds")) {
       char user[100], pass[100];
@@ -346,10 +346,10 @@ static void eh1(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
     } else if (mg_http_match_uri(hm, "/upload")) {
       mg_http_upload(c, hm, ".");
     } else if (mg_http_match_uri(hm, "/test/")) {
-      struct mg_http_serve_opts opts = {".", NULL};
+      struct mg_http_serve_opts opts = {".", NULL, "A: B\r\nC: D\r\n"};
       mg_http_serve_dir(c, hm, &opts);
     } else {
-      struct mg_http_serve_opts opts = {"./test/data", "#.shtml"};
+      struct mg_http_serve_opts opts = {"./test/data", "#.shtml", "C: D\r\n"};
       mg_http_serve_dir(c, hm, &opts);
     }
   } else if (ev == MG_EV_WS_MSG) {