diff --git a/lib/procfile.js b/lib/procfile.js
index dbef824..6050488 100644
--- a/lib/procfile.js
+++ b/lib/procfile.js
@@ -112,8 +112,8 @@ function readProcFile (pid, options, done) {
         cpu: cpu,
         memory: memory,
         ctime: (stat.utime + stat.stime) / cpuInfo.clockTick,
-        elapsed: date - (stat.start * 1000),
-        timestamp: stat.start * 1000, // start date
+        elapsed: (stat.uptime * 1000) - (stat.start * 1000), // process uptime minus start time
+        timestamp: date,
         pid: pid,
         ppid: stat.ppid
       })