diff --git a/libcontainer/system/proc.go b/libcontainer/system/proc.go
index a0e96371..4ffb8331 100644
--- a/libcontainer/system/proc.go
+++ b/libcontainer/system/proc.go
@@ -1,23 +1,43 @@
 package system
 
 import (
+	"fmt"
 	"io/ioutil"
 	"path/filepath"
 	"strconv"
 	"strings"
 )
 
-// look in /proc to find the process start time so that we can verify
-// that this pid has started after ourself
+// Stat_t represents the information from /proc/[pid]/stat, as
+// described in proc(5).
+type Stat_t struct {
+	// StartTime is the number of clock ticks after system boot (since
+	// Linux 2.6).
+	StartTime uint64
+}
+
+// Stat returns a Stat_t instance for the specified process.
+func Stat(pid int) (stat Stat_t, err error) {
+	bytes, err := ioutil.ReadFile(filepath.Join("/proc", strconv.Itoa(pid), "stat"))
+	if err != nil {
+		return stat, err
+	}
+	data := string(bytes)
+	stat.StartTime, err = parseStartTime(data)
+	return stat, err
+}
+
+// GetProcessStartTime is deprecated.  Use Stat(pid) and
+// Stat_t.StartTime instead.
 func GetProcessStartTime(pid int) (string, error) {
-	data, err := ioutil.ReadFile(filepath.Join("/proc", strconv.Itoa(pid), "stat"))
+	stat, err := Stat(pid)
 	if err != nil {
 		return "", err
 	}
-	return parseStartTime(string(data))
+	return fmt.Sprintf("%d", stat.StartTime), nil
 }
 
-func parseStartTime(stat string) (string, error) {
+func parseStartTime(stat string) (uint64, error) {
 	// the starttime is located at pos 22
 	// from the man page
 	//
@@ -39,5 +59,8 @@ func parseStartTime(stat string) (string, error) {
 	// get parts after last `)`:
 	s := strings.Split(stat, ")")
 	parts := strings.Split(strings.TrimSpace(s[len(s)-1]), " ")
-	return parts[22-3], nil // starts at 3 (after the filename pos `2`)
+	startTimeString := parts[22-3] // starts at 3 (after the filename pos `2`)
+	var startTime uint64
+	fmt.Sscanf(startTimeString, "%d", &startTime)
+	return startTime, nil
 }
diff --git a/libcontainer/system/proc_test.go b/libcontainer/system/proc_test.go
index ba910291..c7615ef9 100644
--- a/libcontainer/system/proc_test.go
+++ b/libcontainer/system/proc_test.go
@@ -3,10 +3,10 @@ package system
 import "testing"
 
 func TestParseStartTime(t *testing.T) {
-	data := map[string]string{
-		"4902 (gunicorn: maste) S 4885 4902 4902 0 -1 4194560 29683 29929 61 83 78 16 96 17 20 0 1 0 9126532 52965376 1903 18446744073709551615 4194304 7461796 140733928751520 140733928698072 139816984959091 0 0 16781312 137447943 1 0 0 17 3 0 0 9 0 0 9559488 10071156 33050624 140733928758775 140733928758945 140733928758945 140733928759264 0": "9126532",
-		"9534 (cat) R 9323 9534 9323 34828 9534 4194304 95 0 0 0 0 0 0 0 20 0 1 0 9214966 7626752 168 18446744073709551615 4194304 4240332 140732237651568 140732237650920 140570710391216 0 0 0 0 0 0 0 17 1 0 0 0 0 0 6340112 6341364 21553152 140732237653865 140732237653885 140732237653885 140732237656047 0":                                      "9214966",
-		"24767 (irq/44-mei_me) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 -51 0 1 0 8722075 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 0 0 0 17 1 50 1 0 0 0 0 0 0 0 0 0 0 0":                                                                                                                                                                         "8722075",
+	data := map[string]uint64{
+		"4902 (gunicorn: maste) S 4885 4902 4902 0 -1 4194560 29683 29929 61 83 78 16 96 17 20 0 1 0 9126532 52965376 1903 18446744073709551615 4194304 7461796 140733928751520 140733928698072 139816984959091 0 0 16781312 137447943 1 0 0 17 3 0 0 9 0 0 9559488 10071156 33050624 140733928758775 140733928758945 140733928758945 140733928759264 0": 9126532,
+		"9534 (cat) R 9323 9534 9323 34828 9534 4194304 95 0 0 0 0 0 0 0 20 0 1 0 9214966 7626752 168 18446744073709551615 4194304 4240332 140732237651568 140732237650920 140570710391216 0 0 0 0 0 0 0 17 1 0 0 0 0 0 6340112 6341364 21553152 140732237653865 140732237653885 140732237653885 140732237656047 0":                                      9214966,
+		"24767 (irq/44-mei_me) S 2 0 0 0 -1 2129984 0 0 0 0 0 0 0 0 -51 0 1 0 8722075 0 0 18446744073709551615 0 0 0 0 0 0 0 2147483647 0 0 0 0 17 1 50 1 0 0 0 0 0 0 0 0 0 0 0":                                                                                                                                                                         8722075,
 	}
 	for line, startTime := range data {
 		st, err := parseStartTime(line)