diff --git a/src/AccessLogHandler.php b/src/AccessLogHandler.php
index 30a86b8..672594a 100644
--- a/src/AccessLogHandler.php
+++ b/src/AccessLogHandler.php
@@ -15,9 +15,13 @@ class AccessLogHandler
     /** @var SapiHandler */
     private $sapi;
 
+    /** @var bool */
+    private $hasHighResolution;
+
     public function __construct()
     {
         $this->sapi = new SapiHandler();
+        $this->hasHighResolution = \function_exists('hrtime'); // PHP 7.3+
     }
 
     /**
@@ -25,21 +29,22 @@ public function __construct()
      */
     public function __invoke(ServerRequestInterface $request, callable $next)
     {
+        $now = $this->now();
         $response = $next($request);
 
         if ($response instanceof PromiseInterface) {
-            return $response->then(function (ResponseInterface $response) use ($request) {
-                $this->logWhenClosed($request, $response);
+            return $response->then(function (ResponseInterface $response) use ($request, $now) {
+                $this->logWhenClosed($request, $response, $now);
                 return $response;
             });
         } elseif ($response instanceof \Generator) {
-            return (function (\Generator $generator) use ($request) {
+            return (function (\Generator $generator) use ($request, $now) {
                 $response = yield from $generator;
-                $this->logWhenClosed($request, $response);
+                $this->logWhenClosed($request, $response, $now);
                 return $response;
             })($response);
         } else {
-            $this->logWhenClosed($request, $response);
+            $this->logWhenClosed($request, $response, $now);
             return $response;
         }
     }
@@ -47,7 +52,7 @@ public function __invoke(ServerRequestInterface $request, callable $next)
     /**
      * checks if response body is closed (not streaming) before writing log message for response
      */
-    private function logWhenClosed(ServerRequestInterface $request, ResponseInterface $response): void
+    private function logWhenClosed(ServerRequestInterface $request, ResponseInterface $response, float $start): void
     {
         $body = $response->getBody();
 
@@ -57,23 +62,23 @@ private function logWhenClosed(ServerRequestInterface $request, ResponseInterfac
                 $size += strlen($chunk);
             });
 
-            $body->on('close', function () use (&$size, $request, $response) {
-                $this->log($request, $response, $size);
+            $body->on('close', function () use (&$size, $request, $response, $start) {
+                $this->log($request, $response, $size, $this->now() - $start);
             });
         } else {
-            $this->log($request, $response, $body->getSize() ?? strlen((string) $body));
+            $this->log($request, $response, $body->getSize() ?? strlen((string) $body), $this->now() - $start);
         }
     }
 
     /**
      * writes log message for response after response body is closed (not streaming anymore)
      */
-    private function log(ServerRequestInterface $request, ResponseInterface $response, int $responseSize): void
+    private function log(ServerRequestInterface $request, ResponseInterface $response, int $responseSize, float $time): void
     {
         $this->sapi->log(
             ($request->getServerParams()['REMOTE_ADDR'] ?? '-') . ' ' .
             '"' . $this->escape($request->getMethod()) . ' ' . $this->escape($request->getRequestTarget()) . ' HTTP/' . $request->getProtocolVersion() . '" ' .
-            $response->getStatusCode() . ' ' . $responseSize
+            $response->getStatusCode() . ' ' . $responseSize . ' ' . sprintf('%.3F', $time < 0 ? 0 : $time)
         );
     }
 
@@ -83,4 +88,9 @@ private function escape(string $s): string
             return str_replace('%', '\x', rawurlencode($m[0]));
         }, $s);
     }
+
+    private function now(): float
+    {
+        return $this->hasHighResolution ? hrtime(true) * 1e-9 : microtime(true);
+    }
 }
diff --git a/tests/AccessLogHandlerTest.php b/tests/AccessLogHandlerTest.php
index 69ae0f6..b53c6d2 100644
--- a/tests/AccessLogHandlerTest.php
+++ b/tests/AccessLogHandlerTest.php
@@ -18,8 +18,8 @@ public function testInvokePrintsRequestLogWithCurrentDateAndTime()
         $request = new ServerRequest('GET', 'http://localhost:8080/users', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
         $response = new Response(200, [], "Hello\n");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -30,8 +30,8 @@ public function testInvokePrintsRequestWithQueryParametersLogWithCurrentDateAndT
         $request = new ServerRequest('GET', 'http://localhost:8080/?a=1&b=hello wörld', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
         $response = new Response(200, [], "Hello\n");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /?a=1&b=hello%20w%C3%B6rld HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/\?a=1&b=hello%20w%C3%B6rld HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /?a=1&b=hello%20w%C3%B6rld HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/\?a=1&b=hello%20w%C3%B6rld HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -43,8 +43,8 @@ public function testInvokePrintsRequestWithEscapedSpecialCharactersInRequestMeth
         $request = $request->withRequestTarget('/wörld');
         $response = new Response(200, [], "Hello\n");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GE\x22T /w\xC3\xB6rld HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GE\\\\x22T \/w\\\\xC3\\\\xB6rld HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GE\x22T /w\xC3\xB6rld HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GE\\\\x22T \/w\\\\xC3\\\\xB6rld HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -56,8 +56,8 @@ public function testInvokePrintsPlainProxyRequestLogWithCurrentDateAndTime()
         $request = $request->withRequestTarget('http://localhost:8080/users');
         $response = new Response(400, [], "");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET http://localhost:8080/users HTTP/1.1" 400 0\n
-        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET http://localhost:8080/users HTTP/1\.1\" 400 0" . PHP_EOL . "$#");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET http://localhost:8080/users HTTP/1.1" 400 0 0.000\n
+        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET http://localhost:8080/users HTTP/1\.1\" 400 0 0\.0\d\d" . PHP_EOL . "$#");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -69,8 +69,8 @@ public function testInvokePrintsConnectProxyRequestLogWithCurrentDateAndTime()
         $request = $request->withRequestTarget('example.com:8080');
         $response = new Response(400, [], "");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "CONNECT example.com:8080 HTTP/1.1" 400 0\n
-        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"CONNECT example.com:8080 HTTP/1\.1\" 400 0" . PHP_EOL . "$#");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "CONNECT example.com:8080 HTTP/1.1" 400 0 0.000\n
+        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"CONNECT example.com:8080 HTTP/1\.1\" 400 0 0\.0\d\d" . PHP_EOL . "$#");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -82,8 +82,8 @@ public function testInvokePrintsOptionsAsteriskLogWithCurrentDateAndTime()
         $request = $request->withRequestTarget('*');
         $response = new Response(400, [], "");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "OPTIONS * HTTP/1.1" 400 0\n
-        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"OPTIONS \* HTTP/1\.1\" 400 0" . PHP_EOL . "$#");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "OPTIONS * HTTP/1.1" 400 0 0.000\n
+        $this->expectOutputRegex("#^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"OPTIONS \* HTTP/1\.1\" 400 0 0\.0\d\d" . PHP_EOL . "$#");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -94,8 +94,8 @@ public function testInvokeWithDeferredNextPrintsRequestLogWithCurrentDateAndTime
         $request = new ServerRequest('GET', 'http://localhost:8080/users', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
         $response = new Response(200, [], "Hello\n");
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return resolve($response); });
     }
 
@@ -116,8 +116,8 @@ public function testInvokeWithCoroutineNextPrintsRequestLogWithCurrentDateAndTim
         /** @var \Generator $generator */
         $this->assertInstanceOf(\Generator::class, $generator);
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $generator->next();
     }
 
@@ -129,13 +129,29 @@ public function testInvokeWithStreamingResponsePrintsRequestLogWithCurrentDateAn
         $request = new ServerRequest('GET', 'http://localhost:8080/users', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
         $response = new Response(200, [], $stream);
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 10\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 10" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 10 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 10 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
         $stream->write('hello');
         $stream->end('world');
     }
 
+    public function testInvokeWithStreamingResponseThatClosesAfterSomeTimePrintsRequestLogWithCurrentDateAndTime()
+    {
+        $handler = new AccessLogHandler();
+
+        $stream = new ThroughStream();
+        $request = new ServerRequest('GET', 'http://localhost:8080/users', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
+        $response = new Response(200, [], $stream);
+
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 0 0.100\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 0 0\.1\d\d" . PHP_EOL . "$/");
+        $handler($request, function () use ($response) { return $response; });
+
+        usleep(110000); // 100ms + 10ms to account for inaccurate clocks
+        $stream->end();
+    }
+
     public function testInvokeWithClosedStreamingResponsePrintsRequestLogWithCurrentDateAndTime()
     {
         $handler = new AccessLogHandler();
@@ -145,8 +161,8 @@ public function testInvokeWithClosedStreamingResponsePrintsRequestLogWithCurrent
         $request = new ServerRequest('GET', 'http://localhost:8080/users', [], '', '1.1', ['REMOTE_ADDR' => '127.0.0.1']);
         $response = new Response(200, [], $stream);
 
-        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 10\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 0" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 127.0.0.1 "GET /users HTTP/1.1" 200 0 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} 127\.0\.0\.1 \"GET \/users HTTP\/1\.1\" 200 0 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
     }
 
@@ -170,8 +186,8 @@ public function testInvokeWithoutRemoteAddressPrintsRequestLogWithDashAsPlacehol
         $request = new ServerRequest('GET', 'http://localhost:8080/users');
         $response = new Response(200, [], "Hello\n");
 
-        // 2021-01-29 12:22:01.717 - "GET /users HTTP/1.1" 200 6\n
-        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} - \"GET \/users HTTP\/1\.1\" 200 6" . PHP_EOL . "$/");
+        // 2021-01-29 12:22:01.717 - "GET /users HTTP/1.1" 200 6 0.000\n
+        $this->expectOutputRegex("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} - \"GET \/users HTTP\/1\.1\" 200 6 0\.0\d\d" . PHP_EOL . "$/");
         $handler($request, function () use ($response) { return $response; });
     }
 }