diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c

index 8b5975c..9e12243 100644

--- a/src/http/v2/ngx_http_v2.c

+++ b/src/http/v2/ngx_http_v2.c

@@ -247,6 +247,8 @@ ngx_http_v2_init(ngx_event_t *rev)

     h2scf = ngx_http_get_module_srv_conf(hc->conf_ctx, ngx_http_v2_module);

+    h2c->priority_limit = h2scf->concurrent_streams;

+

     h2c->pool = ngx_create_pool(h2scf->pool_size, h2c->connection->log);

     if (h2c->pool == NULL) {

         ngx_http_close_connection(c);

@@ -1786,6 +1788,13 @@ ngx_http_v2_state_priority(ngx_http_v2_connection_t *h2c, u_char *pos,

         return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_SIZE_ERROR);

     }

+    if (--h2c->priority_limit == 0) {

+        ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0,

+                      "client sent too many PRIORITY frames");

+

+        return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_ENHANCE_YOUR_CALM);

+    }

+

     if (end - pos < NGX_HTTP_V2_PRIORITY_SIZE) {

         return ngx_http_v2_state_save(h2c, pos, end,

                                       ngx_http_v2_state_priority);

@@ -2846,6 +2855,8 @@ ngx_http_v2_create_stream(ngx_http_v2_connection_t *h2c)

     h2c->processing++;

+    h2c->priority_limit += h2scf->concurrent_streams;

+

     return stream;

 }

diff --git a/src/http/v2/ngx_http_v2.h b/src/http/v2/ngx_http_v2.h

index 282de8f..4a74a6a 100644

--- a/src/http/v2/ngx_http_v2.h

+++ b/src/http/v2/ngx_http_v2.h

@@ -117,6 +117,7 @@ struct ngx_http_v2_connection_s {

     ngx_uint_t                       processing;

     ngx_uint_t                       frames;

     ngx_uint_t                       idle;

+    ngx_uint_t                       priority_limit;

     size_t                           send_window;

     size_t                           recv_window;