diff --git a/Gemfile.lock b/Gemfile.lock
index 7bc16a8ed..8d56e22bf 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    kiba-extend (2.5.0)
+    kiba-extend (2.5.1)
       activesupport (~> 6.1.4)
       csv (~> 3.0)
       dry-configurable (~> 0.11)
@@ -108,4 +108,4 @@ DEPENDENCIES
   simplecov
 
 BUNDLED WITH
-   2.1.4
+   2.2.22
diff --git a/lib/kiba/extend/destinations/csv.rb b/lib/kiba/extend/destinations/csv.rb
index 70e2e2321..6d2014055 100644
--- a/lib/kiba/extend/destinations/csv.rb
+++ b/lib/kiba/extend/destinations/csv.rb
@@ -27,6 +27,7 @@ def initialize(filename:, csv_options: nil, headers: nil, initial_headers: [])
         def write(row)
           @csv ||= ::CSV.open(filename, 'wb', **csv_options)
           @headers ||= row.keys
+          verify_initial_headers
           order_headers
           @headers_written ||= (csv << headers; true)
           csv << row.fetch_values(*@headers)
@@ -39,10 +40,34 @@ def close
 
         private
 
+        def header_check_hash
+          @initial_headers.map{ |hdr| [hdr, headers.any?(hdr)] }.to_h
+        end
+
+        def initial_headers_present?
+          header_check_hash.values.all?(true)
+        end
+
+        def missing_initial_headers
+          header_check_hash.reject{ |hdr, present| present }.keys
+        end
+        
         def order_headers
           remainder = @headers - @initial_headers
           @headers = [@initial_headers, remainder].flatten
         end
+
+        def verify_initial_headers
+          return if @initial_headers.empty?
+          return if initial_headers_present?
+
+          missing = missing_initial_headers
+
+          missing.each do |hdr|
+            puts "WARNING: Output data does not contain specified initial header: #{hdr}"
+          end
+          @initial_headers = @initial_headers - missing
+        end
       end
     end
   end
diff --git a/lib/kiba/extend/version.rb b/lib/kiba/extend/version.rb
index 4f6f88a67..62588ffef 100644
--- a/lib/kiba/extend/version.rb
+++ b/lib/kiba/extend/version.rb
@@ -2,6 +2,6 @@
 
 module Kiba
   module Extend
-    VERSION = '2.5.0'
+    VERSION = '2.5.1'
   end
 end
diff --git a/spec/kiba/extend/destinations/csv_spec.rb b/spec/kiba/extend/destinations/csv_spec.rb
new file mode 100644
index 000000000..92235a67b
--- /dev/null
+++ b/spec/kiba/extend/destinations/csv_spec.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Kiba::Extend::Destinations::CSV do
+  TEST_FILENAME = 'output.csv'
+  def run_job(input)
+    job = Kiba.parse do
+      source Kiba::Common::Sources::Enumerable, input
+      destination Kiba::Extend::Destinations::CSV, filename: TEST_FILENAME, initial_headers: %i[y z]
+    end
+
+    Kiba.run(job)
+
+    IO.read(TEST_FILENAME)
+  end
+
+  after(:each){ File.delete(TEST_FILENAME) if File.exist?(TEST_FILENAME) }
+
+  context 'when intial headers present' do
+    let(:input) do
+      [
+        {a: 'and', y: 'yak', z: 'zebra'},
+        {a: 'apple', y: 'yarrow', z: 'zizia'}
+      ]
+    end
+    let(:expected) do
+      "y,z,a\nyak,zebra,and\nyarrow,zizia,apple\n"
+    end
+    it 'produces CSV as expected' do
+      expect(run_job(input)).to eq(expected)
+    end
+  end
+
+  context 'when intial headers specified but not present' do
+    let(:input) do
+      [
+        {a: 'and', z: 'zebra'},
+        {a: 'apple', z: 'zizia'}
+      ]
+    end
+    let(:expected) do
+      "z,a\nzebra,and\nzizia,apple\n"
+    end
+    it 'produces CSV as expected' do
+      expect(run_job(input)).to eq(expected)
+    end
+    it 'writes warning to STDOUT' do
+      msg = 'Output data does not contain specified initial header: y'
+      expect { run_job(input) }.to output(/#{msg}/).to_stdout
+    end
+  end
+end
+
diff --git a/spec/kiba/extend/destinations/json_array_spec.rb b/spec/kiba/extend/destinations/json_array_spec.rb
index d35887eab..e7b0833d1 100644
--- a/spec/kiba/extend/destinations/json_array_spec.rb
+++ b/spec/kiba/extend/destinations/json_array_spec.rb
@@ -2,20 +2,20 @@
 
 require 'spec_helper'
 
-TEST_FILENAME = 'output.json'
+RSpec.describe Kiba::Extend::Destinations::JsonArray do
+  TEST_FILENAME = 'output.json'
 
-def run_job(input)
-  job = Kiba.parse do
-    source Kiba::Common::Sources::Enumerable, input
-    destination Kiba::Extend::Destinations::JsonArray, filename: TEST_FILENAME
-  end
+  def run_job(input)
+    job = Kiba.parse do
+      source Kiba::Common::Sources::Enumerable, input
+      destination Kiba::Extend::Destinations::JsonArray, filename: TEST_FILENAME
+    end
 
-  Kiba.run(job)
+    Kiba.run(job)
 
-  IO.read(TEST_FILENAME)
-end
+    IO.read(TEST_FILENAME)
+  end
 
-RSpec.describe Kiba::Extend::Destinations::JsonArray do
   after(:each){ File.delete(TEST_FILENAME) if File.exist?(TEST_FILENAME) }
 
   context 'when simplest data ever' do