diff --git a/vendor/github.com/prometheus/common/model/value.go b/vendor/github.com/prometheus/common/model/value.go
index dbf5d10e4..7728abaee 100644
--- a/vendor/github.com/prometheus/common/model/value.go
+++ b/vendor/github.com/prometheus/common/model/value.go
@@ -22,6 +22,22 @@ import (
 	"strings"
 )
 
+var (
+	// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
+	// non-existing sample pair. It is a SamplePair with timestamp Earliest and
+	// value 0.0. Note that the natural zero value of SamplePair has a timestamp
+	// of 0, which is possible to appear in a real SamplePair and thus not
+	// suitable to signal a non-existing SamplePair.
+	ZeroSamplePair = SamplePair{Timestamp: Earliest}
+
+	// ZeroSample is the pseudo zero-value of Sample used to signal a
+	// non-existing sample. It is a Sample with timestamp Earliest, value 0.0,
+	// and metric nil. Note that the natural zero value of Sample has a timestamp
+	// of 0, which is possible to appear in a real Sample and thus not suitable
+	// to signal a non-existing Sample.
+	ZeroSample = Sample{Timestamp: Earliest}
+)
+
 // A SampleValue is a representation of a value for a given sample at a given
 // time.
 type SampleValue float64
diff --git a/vendor/vendor.json b/vendor/vendor.json
index e983daae3..a14c4dd36 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -205,8 +205,8 @@
 		{
 			"checksumSHA1": "Jx0GXl5hGnO25s3ryyvtdWHdCpw=",
 			"path": "github.com/prometheus/common/model",
-			"revision": "4402f4e5ea79ec15f3c574773b6a5198fbea215f",
-			"revisionTime": "2016-06-23T15:14:27Z"
+			"revision": "e35a2e33a50a7d756c7afdfaf609f93905a0c111",
+			"revisionTime": "2016-09-28T14:38:18+02:00"
 		},
 		{
 			"checksumSHA1": "CKVJRc1NREmfoAWQLHxqWQlvxo0=",