diff --git a/README.md b/README.md
index e150a85e..2582917d 100644
--- a/README.md
+++ b/README.md
@@ -110,6 +110,8 @@ Versioning is strictly based on [Semantic Versioning](https://semver.org/)
 * fix: properly log line numbers by using tail calls [#29](https://github.com/Kong/lua-resty-healthcheck/pull/29)
 * fix: when not providing a hostname, use IP [#48](https://github.com/Kong/lua-resty-healthcheck/pull/48)
 * fix: makefile; make install
+* feature: added a status version field [#54](https://github.com/Kong/lua-resty-healthcheck/pull/54)
+* feature: add headers for probe request [#54](https://github.com/Kong/lua-resty-healthcheck/pull/54)
 
 ### 1.3.0 (17-Jun-2020)
 
diff --git a/lib/resty/healthcheck.lua b/lib/resty/healthcheck.lua
index 1685edc9..58eeeb8d 100644
--- a/lib/resty/healthcheck.lua
+++ b/lib/resty/healthcheck.lua
@@ -850,8 +850,15 @@ function checker:run_single_check(ip, port, hostname, hostheader)
 
   end
 
+  local req_headers = self.checks.active.headers
+  local headers = table.concat(req_headers, "\r\n")
+  if #headers > 0 then
+    headers = headers .. "\r\n"
+  end
+
   local path = self.checks.active.http_path
-  local request = ("GET %s HTTP/1.0\r\nHost: %s\r\n\r\n"):format(path, hostheader or hostname)
+  local request = ("GET %s HTTP/1.0\r\n%sHost: %s\r\n\r\n"):format(path, headers, hostheader or hostname or ip)
+  self:log(DEBUG, "request head: ", request)
 
   local bytes
   bytes, err = sock:send(request)
@@ -1076,11 +1083,17 @@ function checker:event_handler(event_name, ip, port, hostname)
       self:log(DEBUG, "event: target added '", hostname or "", "(", ip, ":", port, ")'")
     end
     do
-      local from = target_found.internal_health
-      local to = event_name
-      self:log(DEBUG, "event: target status '", hostname or "", "(", ip, ":", port,
-                      ")' from '", from == "healthy" or from == "mostly_healthy",
-                      "' to '",   to   == "healthy" or to   == "mostly_healthy", "'")
+      local from_status = target_found.internal_health
+      local to_status = event_name
+      local from = from_status == "healthy" or from_status == "mostly_healthy"
+      local to = to_status == "healthy" or to_status == "mostly_healthy"
+
+      if from ~= to then
+        self.status_ver = self.status_ver + 1
+      end
+
+      self:log(DEBUG, "event: target status '", hostname or "", "(", ip, ":",
+               port, ")' from '", from, "' to '", to, "', ver: ", self.status_ver)
     end
     target_found.internal_health = event_name
 
@@ -1214,6 +1227,7 @@ local defaults = {
   name = NO_DEFAULT,
   shm_name = NO_DEFAULT,
   type = NO_DEFAULT,
+  status_ver = 0,
   checks = {
     active = {
       type = "http",
@@ -1222,6 +1236,7 @@ local defaults = {
       http_path = "/",
       https_sni = NO_DEFAULT,
       https_verify_certificate = true,
+      headers = {""},
       healthy = {
         interval = 0, -- 0 = disabled by default
         http_statuses = { 200, 302 },
@@ -1294,6 +1309,7 @@ end
 -- * `checks.active.http_path`: path to use in `GET` HTTP request to run on active checks
 -- * `checks.active.https_sni`: SNI server name incase of HTTPS
 -- * `checks.active.https_verify_certificate`: boolean indicating whether to verify the HTTPS certificate
+-- * `checks.active.hheaders`: an array of headers (no hash-table! must be pre-formatted)
 -- * `checks.active.healthy.interval`: interval between checks for healthy targets (in seconds)
 -- * `checks.active.healthy.http_statuses`: which HTTP statuses to consider a success
 -- * `checks.active.healthy.successes`: number of successes to consider a target healthy
diff --git a/t/19-status-ver.t b/t/19-status-ver.t
new file mode 100644
index 00000000..c7d2166f
--- /dev/null
+++ b/t/19-status-ver.t
@@ -0,0 +1,62 @@
+use Test::Nginx::Socket::Lua 'no_plan';
+use Cwd qw(cwd);
+
+workers(2);
+master_on();
+
+my $pwd = cwd();
+
+our $HttpConfig = qq{
+    lua_package_path "$pwd/lib/?.lua;;";
+    lua_shared_dict test_shm 8m;
+    lua_shared_dict my_worker_events 8m;
+
+    init_worker_by_lua_block {
+        local we = require "resty.worker.events"
+        assert(we.configure{ shm = "my_worker_events", interval = 0.1 })
+        ngx.timer.at(0, function()
+            local healthcheck = require("resty.healthcheck")
+            local checker = healthcheck.new({
+                name = "testing",
+                shm_name = "test_shm",
+                checks = {
+                    active = {
+                        healthy  = {
+                            interval = 0.1
+                        },
+                        unhealthy  = {
+                            interval = 0.1
+                        }
+                    }
+                }
+            })
+            local ok, err = checker:add_target("127.0.0.1", 11111)
+            if not ok then
+                error(err)
+            end
+        end)
+    }
+};
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: add_target() adds an unhealthy target
+--- http_config eval: $::HttpConfig
+--- config
+    location = /t {
+        content_by_lua_block {
+            ngx.say(true)
+            ngx.sleep(0.3) -- wait twice the interval
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+--- error_log
+checking unhealthy targets: nothing to do
+checking unhealthy targets: #1
+from 'true' to 'false', ver: 2
+from 'true' to 'false', ver: 1
diff --git a/t/20-req-headers.t b/t/20-req-headers.t
new file mode 100644
index 00000000..304315db
--- /dev/null
+++ b/t/20-req-headers.t
@@ -0,0 +1,114 @@
+use Test::Nginx::Socket::Lua 'no_plan';
+use Cwd qw(cwd);
+
+workers(1);
+
+my $pwd = cwd();
+
+our $HttpConfig = qq{
+    lua_package_path "$pwd/lib/?.lua;;";
+    lua_shared_dict test_shm 8m;
+    lua_shared_dict my_worker_events 8m;
+};
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: headers: {"User-Agent", "curl/7.29.0"}
+--- http_config eval
+qq{
+    $::HttpConfig
+
+    server {
+        listen 2112;
+        location = /status {
+            return 200;
+        }
+    }
+}
+--- config
+    location = /t {
+        content_by_lua_block {
+            local we = require "resty.worker.events"
+            assert(we.configure{ shm = "my_worker_events", interval = 0.1 })
+            local healthcheck = require("resty.healthcheck")
+            local checker = healthcheck.new({
+                name = "testing",
+                shm_name = "test_shm",
+                checks = {
+                    active = {
+                        http_path = "/status",
+                        healthy  = {
+                            interval = 0.1
+                        },
+                        headers = {"User-Agent: curl/7.29.0"}
+                    }
+                }
+            })
+            ngx.sleep(0.2) -- wait twice the interval
+            local ok, err = checker:add_target("127.0.0.1", 2112, nil, true)
+            ngx.say(ok)
+            ngx.sleep(0.2) -- wait twice the interval
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+--- error_log
+checking healthy targets: nothing to do
+checking healthy targets: #1
+GET /status HTTP/1.0
+User-Agent: curl/7.29.0
+Host: 127.0.0.1
+
+
+
+=== TEST 2: headers: {"User-Agent", "curl"}
+--- http_config eval
+qq{
+    $::HttpConfig
+
+    server {
+        listen 2112;
+        location = /status {
+            return 200;
+        }
+    }
+}
+--- config
+    location = /t {
+        content_by_lua_block {
+            local we = require "resty.worker.events"
+            assert(we.configure{ shm = "my_worker_events", interval = 0.1 })
+            local healthcheck = require("resty.healthcheck")
+            local checker = healthcheck.new({
+                name = "testing",
+                shm_name = "test_shm",
+                checks = {
+                    active = {
+                        http_path = "/status",
+                        healthy  = {
+                            interval = 0.1
+                        },
+                        headers = {"User-Agent: curl"}
+                    }
+                }
+            })
+            ngx.sleep(0.2) -- wait twice the interval
+            local ok, err = checker:add_target("127.0.0.1", 2112, nil, true)
+            ngx.say(ok)
+            ngx.sleep(0.2) -- wait twice the interval
+        }
+    }
+--- request
+GET /t
+--- response_body
+true
+--- error_log
+checking healthy targets: nothing to do
+checking healthy targets: #1
+GET /status HTTP/1.0
+User-Agent: curl
+Host: 127.0.0.1