diff --git a/promql/value.go b/promql/value.go
index 5ca7c3493..0d5181583 100644
--- a/promql/value.go
+++ b/promql/value.go
@@ -158,7 +158,7 @@ func (vec Vector) ContainsSameLabelset() bool {
 	return false
 }
 
-// Matrix is a slice of Seriess that implements sort.Interface and
+// Matrix is a slice of Series that implements sort.Interface and
 // has a String method.
 type Matrix []Series