diff --git a/mongoose.c b/mongoose.c
index 99d8072e..65cf7076 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -1344,6 +1344,7 @@ void mg_http_serve_file(struct mg_connection *c, struct mg_http_message *hm,
               status, mg_http_status_code_str(status), (int) mime.len, mime.ptr,
               etag, cl, range, opts->extra_headers ? opts->extra_headers : "");
     if (mg_vcasecmp(&hm->method, "HEAD") == 0) {
+      c->is_draining = 1;
       fs->close(fd);
     } else {
       c->pfn = static_cb;
@@ -3091,23 +3092,24 @@ static void write_conn(struct mg_connection *c) {
 }
 
 static void close_conn(struct mg_connection *c) {
-  // Unlink this connection from the list
-  mg_resolve_cancel(c);
+  mg_resolve_cancel(c);  // Close any pending DNS query
   LIST_DELETE(struct mg_connection, &c->mgr->conns, c);
   if (c == c->mgr->dns4.c) c->mgr->dns4.c = NULL;
   if (c == c->mgr->dns6.c) c->mgr->dns6.c = NULL;
+  // Order of operations is important. `MG_EV_CLOSE` event must be fired
+  // before we deallocate received data, see #1331
   mg_call(c, MG_EV_CLOSE, NULL);
-  // while (c->callbacks != NULL) mg_fn_del(c, c->callbacks->fn);
   LOG(LL_DEBUG, ("%lu closed", c->id));
   if (FD(c) != INVALID_SOCKET) {
     closesocket(FD(c));
 #if MG_ARCH == MG_ARCH_FREERTOS_TCP
     FreeRTOS_FD_CLR(c->fd, c->mgr->ss, eSELECT_ALL);
 #endif
+    c->fd = S2PTR(INVALID_SOCKET);
   }
   mg_tls_free(c);
-  free(c->recv.buf);
-  free(c->send.buf);
+  mg_iobuf_free(&c->recv);
+  mg_iobuf_free(&c->send);
   memset(c, 0, sizeof(*c));
   free(c);
 }
diff --git a/src/http.c b/src/http.c
index dfc30827..c9be9ef4 100644
--- a/src/http.c
+++ b/src/http.c
@@ -573,6 +573,7 @@ void mg_http_serve_file(struct mg_connection *c, struct mg_http_message *hm,
               status, mg_http_status_code_str(status), (int) mime.len, mime.ptr,
               etag, cl, range, opts->extra_headers ? opts->extra_headers : "");
     if (mg_vcasecmp(&hm->method, "HEAD") == 0) {
+      c->is_draining = 1;
       fs->close(fd);
     } else {
       c->pfn = static_cb;
diff --git a/src/sock.c b/src/sock.c
index 255f6ad1..4fda912d 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -265,23 +265,24 @@ static void write_conn(struct mg_connection *c) {
 }
 
 static void close_conn(struct mg_connection *c) {
-  // Unlink this connection from the list
-  mg_resolve_cancel(c);
+  mg_resolve_cancel(c);  // Close any pending DNS query
   LIST_DELETE(struct mg_connection, &c->mgr->conns, c);
   if (c == c->mgr->dns4.c) c->mgr->dns4.c = NULL;
   if (c == c->mgr->dns6.c) c->mgr->dns6.c = NULL;
+  // Order of operations is important. `MG_EV_CLOSE` event must be fired
+  // before we deallocate received data, see #1331
   mg_call(c, MG_EV_CLOSE, NULL);
-  // while (c->callbacks != NULL) mg_fn_del(c, c->callbacks->fn);
   LOG(LL_DEBUG, ("%lu closed", c->id));
   if (FD(c) != INVALID_SOCKET) {
     closesocket(FD(c));
 #if MG_ARCH == MG_ARCH_FREERTOS_TCP
     FreeRTOS_FD_CLR(c->fd, c->mgr->ss, eSELECT_ALL);
 #endif
+    c->fd = S2PTR(INVALID_SOCKET);
   }
   mg_tls_free(c);
-  free(c->recv.buf);
-  free(c->send.buf);
+  mg_iobuf_free(&c->recv);
+  mg_iobuf_free(&c->send);
   memset(c, 0, sizeof(*c));
   free(c);
 }