--- a/src/http/modules/ngx_http_range_filter_module.c
+++ b/src/http/modules/ngx_http_range_filter_module.c
@@ -146,7 +146,8 @@ static ngx_http_output_body_filter_pt   
 static ngx_int_t
 ngx_http_range_header_filter(ngx_http_request_t *r)
 {
-    time_t                        if_range;
+    time_t                        if_range_time;
+    ngx_str_t                    *if_range, *etag;
     ngx_http_core_loc_conf_t     *clcf;
     ngx_http_range_filter_ctx_t  *ctx;
 
@@ -176,22 +177,45 @@ ngx_http_range_header_filter(ngx_http_re
 
     if (r->headers_in.if_range) {
 
+        if_range = &r->headers_in.if_range->value;
+
+        if (if_range->len > 2 && if_range->data[if_range->len - 1] == '"') {
+
+            if (r->headers_out.etag == NULL) {
+                goto next_filter;
+            }
+
+            etag = &r->headers_out.etag->value;
+
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "http ir:%V etag:%V", if_range, etag);
+
+            if (if_range->len != etag->len
+                || ngx_strncmp(if_range->data, etag->data, etag->len) != 0)
+            {
+                goto next_filter;
+            }
+
+            goto parse;
+        }
+
         if (r->headers_out.last_modified_time == (time_t) -1) {
             goto next_filter;
         }
 
-        if_range = ngx_http_parse_time(r->headers_in.if_range->value.data,
-                                       r->headers_in.if_range->value.len);
+        if_range_time = ngx_http_parse_time(if_range->data, if_range->len);
 
         ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                        "http ir:%d lm:%d",
-                       if_range, r->headers_out.last_modified_time);
+                       if_range_time, r->headers_out.last_modified_time);
 
-        if (if_range != r->headers_out.last_modified_time) {
+        if (if_range_time != r->headers_out.last_modified_time) {
             goto next_filter;
         }
     }
 
+parse:
+
     ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_range_filter_ctx_t));
     if (ctx == NULL) {
         return NGX_ERROR;