diff --git a/src/http/ngx_http_script.c b/src/http/ngx_http_script.c
index 1a87735..4153889 100644
--- a/src/http/ngx_http_script.c
+++ b/src/http/ngx_http_script.c
@@ -271,6 +271,34 @@
 }
 
 
+ngx_int_t
+ngx_http_test_required_predicates(ngx_http_request_t *r,
+    ngx_array_t *predicates)
+{
+    ngx_str_t                  val;
+    ngx_uint_t                 i;
+    ngx_http_complex_value_t  *cv;
+
+    if (predicates == NULL) {
+        return NGX_OK;
+    }
+
+    cv = predicates->elts;
+
+    for (i = 0; i < predicates->nelts; i++) {
+        if (ngx_http_complex_value(r, &cv[i], &val) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        if (val.len == 0 || (val.len == 1 && val.data[0] == '0')) {
+            return NGX_DECLINED;
+        }
+    }
+
+    return NGX_OK;
+}
+
+
 char *
 ngx_http_set_predicate_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
diff --git a/src/http/ngx_http_script.h b/src/http/ngx_http_script.h
index a5116d7..25bb6d7 100644
--- a/src/http/ngx_http_script.h
+++ b/src/http/ngx_http_script.h
@@ -214,6 +214,8 @@
 
 ngx_int_t ngx_http_test_predicates(ngx_http_request_t *r,
     ngx_array_t *predicates);
+ngx_int_t ngx_http_test_required_predicates(ngx_http_request_t *r,
+    ngx_array_t *predicates);
 char *ngx_http_set_predicate_slot(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);