diff --git a/vendor/github.com/prometheus/common/model/signature.go b/vendor/github.com/prometheus/common/model/signature.go
index cf14e82c5c..8762b13c63 100644
--- a/vendor/github.com/prometheus/common/model/signature.go
+++ b/vendor/github.com/prometheus/common/model/signature.go
@@ -98,7 +98,7 @@ func labelSetToFastFingerprint(ls LabelSet) Fingerprint {
 // specified LabelNames into the signature calculation. The labels passed in
 // will be sorted by this function.
 func SignatureForLabels(m Metric, labels ...LabelName) uint64 {
-	if len(m) == 0 || len(labels) == 0 {
+	if len(labels) == 0 {
 		return emptyLabelSignature
 	}
 
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 8cfe495432..e621008795 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -174,8 +174,8 @@
 		},
 		{
 			"path": "github.com/prometheus/common/model",
-			"revision": "0e53cc19aa67dd2e8587a26e28643cb152f5403d",
-			"revisionTime": "2016-01-29T15:16:16+01:00"
+			"revision": "167b27da48d058a9b46d84b834d67f68f0243f67",
+			"revisionTime": "2016-03-18T12:23:18Z"
 		},
 		{
 			"path": "github.com/prometheus/common/route",