diff --git a/spec/haversine/distance_spec.cr b/spec/haversine/distance_spec.cr
index 519627c..bf72999 100644
--- a/spec/haversine/distance_spec.cr
+++ b/spec/haversine/distance_spec.cr
@@ -23,5 +23,6 @@ describe Haversine::Distance do
 
     it { (dist1 + dist2).distance.should eq(3) }
     it { (dist1 - dist2).distance.should eq(1) }
+    it { [dist1, dist2].sum.distance.should eq(3) }
   end
 end
diff --git a/src/haversine/distance.cr b/src/haversine/distance.cr
index 30bd6a4..81406fb 100644
--- a/src/haversine/distance.cr
+++ b/src/haversine/distance.cr
@@ -17,6 +17,10 @@ module Haversine
       distance <=> other.distance
     end
 
+    def self.zero : Haversine::Distance
+      new(0)
+    end
+
     # Adds the value of `self` to *other*.
     def +(other : Haversine::Distance) : Haversine::Distance
       Haversine::Distance.new(distance + other.distance)