diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 269a5364..615a368b 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -9,7 +9,7 @@ concurrency:
 jobs:
   tests:
     name: Lint
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
     - name: Checkout source code
diff --git a/README.md b/README.md
index 61ca9de4..9dc047f9 100644
--- a/README.md
+++ b/README.md
@@ -113,7 +113,6 @@ index *commonly used variables* as follows:
 - `$remote_port`
 - `$request_length`
 - `$request_method`
-- `$request_time`
 - `$request_uri`
 - `$scheme`
 - `$server_addr`
diff --git a/src/ngx_http_lua_kong_var_index.c b/src/ngx_http_lua_kong_var_index.c
index 603af155..c1d50c9d 100644
--- a/src/ngx_http_lua_kong_var_index.c
+++ b/src/ngx_http_lua_kong_var_index.c
@@ -71,7 +71,6 @@ static ngx_str_t default_vars[] = {
     /* ngx_string("request"), */
     ngx_string("request_length"),
     ngx_string("request_method"),
-    ngx_string("request_time"),
     ngx_string("request_uri"),
     ngx_string("scheme"),
     ngx_string("server_addr"),
diff --git a/t/006-default_indexed-var.t b/t/006-default_indexed-var.t
index 56c837a6..3efbf963 100644
--- a/t/006-default_indexed-var.t
+++ b/t/006-default_indexed-var.t
@@ -9,7 +9,7 @@ use Test::Nginx::Socket::Lua;
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 8) + 14;
+plan tests => repeat_each() * (blocks() * 8) + 12;
 
 #no_diff();
 #no_long_string();
@@ -205,7 +205,6 @@ get variable value '666' by index
             ngx.say(ngx.var.request_method, " ",
                     ngx.var.request_length, " ",
                     ngx.var.request_uri, " ",
-                    ngx.var.request_time, " ",
                     ngx.var.server_addr, " ",
                     ngx.var.server_port
                     )
@@ -214,12 +213,11 @@ get variable value '666' by index
 --- request
 GET /test
 --- response_body
-GET 58 /test 0.000 127.0.0.1 1984
+GET 58 /test 127.0.0.1 1984
 --- error_log
 get variable value 'GET' by index
 get variable value '58' by index
 get variable value '/test' by index
-get variable value '0.000' by index
 get variable value '127.0.0.1' by index
 get variable value '1984' by index
 --- no_error_log