diff --git a/src/http/ngx_http_variables.c b/src/http/ngx_http_variables.c
index d693731..9137460 100644
--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -41,6 +41,8 @@
     ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_scheme(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_http_variable_is_args(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_document_root(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_variable_request_filename(ngx_http_request_t *r,
@@ -163,6 +165,9 @@
       offsetof(ngx_http_request_t, args),
       NGX_HTTP_VAR_CHANGABLE|NGX_HTTP_VAR_NOCACHABLE, 0 },
 
+    { ngx_string("is_args"), NULL, ngx_http_variable_is_args,
+      0, NGX_HTTP_VAR_NOCACHABLE, 0 },
+
     { ngx_string("request_filename"), NULL,
       ngx_http_variable_request_filename, 0,
       NGX_HTTP_VAR_NOCACHABLE, 0 },
@@ -877,6 +882,27 @@
 
 
 static ngx_int_t
+ngx_http_variable_is_args(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data)
+{
+    v->valid = 1;
+    v->no_cachable = 0;
+    v->not_found = 0;
+
+    if (r->args.len == 0) {
+        v->len = 0;
+        v->data = NULL;
+        return NGX_OK;
+    }
+
+    v->len = 1;
+    v->data = (u_char *) "?";
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_variable_document_root(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {