diff --git a/lib/rackstash/fields/abstract_collection.rb b/lib/rackstash/fields/abstract_collection.rb
index d10120e..3f16bdf 100644
--- a/lib/rackstash/fields/abstract_collection.rb
+++ b/lib/rackstash/fields/abstract_collection.rb
@@ -22,6 +22,16 @@ module Rackstash
       end
       alias eql? ==
 
+      # Compute a hash-code for this collection.
+      #
+      # Two collections with the same raw content will have the same hash code
+      # (and will compare using {#eql?}).
+      #
+      # @return [Integer] the hash ID of `self`
+      def hash
+        [self.class, raw].hash
+      end
+
       # Show a human-readable representation of `self`. To get a machine-
       # readable "export" of the contained data, use {#as_json} or one of its
       # aliases instead.
diff --git a/spec/rackstash/fields/abstract_collection_spec.rb b/spec/rackstash/fields/abstract_collection_spec.rb
index d350e65..b62060f 100644
--- a/spec/rackstash/fields/abstract_collection_spec.rb
+++ b/spec/rackstash/fields/abstract_collection_spec.rb
@@ -91,6 +91,18 @@ describe Rackstash::Fields::AbstractCollection do
     end
   end
 
+  describe '#hash' do
+    it 'returns the same hash for the same raw content' do
+      collection.send(:raw=, [123, 'foo'])
+
+      collection2 = Rackstash::Fields::AbstractCollection.new
+      collection2.send(:raw=, [123, 'foo'])
+
+      expect(collection.send(:raw)).not_to equal collection2.send(:raw)
+      expect(collection.hash).to eql collection2.hash
+    end
+  end
+
   describe '#raw' do
     it 'is a protected accessor' do
       expect { collection.raw = nil }.to raise_error NoMethodError