diff --git a/Gemfile.lock b/Gemfile.lock
index c73da93a2..d9667e4a8 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    kiba-extend (1.2.1)
+    kiba-extend (1.3.0)
       activesupport
       kiba (>= 3.0.0)
       kiba-common (>= 0.9.0)
diff --git a/lib/kiba/extend/transforms/replace.rb b/lib/kiba/extend/transforms/replace.rb
index 61ad19143..eb885249d 100644
--- a/lib/kiba/extend/transforms/replace.rb
+++ b/lib/kiba/extend/transforms/replace.rb
@@ -3,6 +3,22 @@ module Extend
     module Transforms
       module Replace
         ::Replace = Kiba::Extend::Transforms::Replace
+        class EmptyFieldValues
+          def initialize(fields:, value:)
+            @fields = fields
+            @value = value
+          end
+
+          def process(row)
+            blankfields = @fields.map{ |field| [field, row.fetch(field, nil)] }
+              .select{ |pair| pair[1].blank? }
+              .map{ |pair| pair[0] }
+            return row if blankfields.empty?
+            blankfields.each{ |field| row[field] = @value }
+            row
+          end
+        end
+        
         class FieldValueWithStaticMapping
           def initialize(source:, target:, mapping:, fallback_val: :orig, delete_source: true,
                          multival: false, sep: '')
diff --git a/lib/kiba/extend/version.rb b/lib/kiba/extend/version.rb
index a53928e15..b0793aeda 100644
--- a/lib/kiba/extend/version.rb
+++ b/lib/kiba/extend/version.rb
@@ -1,5 +1,5 @@
 module Kiba
   module Extend
-    VERSION = "1.3.0"
+    VERSION = "1.4.0"
   end
 end
diff --git a/spec/kiba/extend/transforms/replace_spec.rb b/spec/kiba/extend/transforms/replace_spec.rb
index 4088cb1b4..2d8fef244 100644
--- a/spec/kiba/extend/transforms/replace_spec.rb
+++ b/spec/kiba/extend/transforms/replace_spec.rb
@@ -1,7 +1,30 @@
 require 'spec_helper'
 
 RSpec.describe Kiba::Extend::Transforms::Replace do
-  describe 'FieldValueWithStaticMapping' do
+  
+  describe 'EmptyFieldValues' do
+    test_csv = 'tmp/test.csv'
+    rows = [
+      ['id', 'species', 'name', 'sex'],
+      [1, 'guineafowl', nil, ''],
+    ]
+
+    before do
+      generate_csv(test_csv, rows)
+    end
+    it 'replaces empty field values in specified field(s) with given string' do
+      expected = [
+        {id: '1', species: 'guineafowl', name: 'NULL', sex: 'NULL'}
+      ]
+      result = execute_job(filename: test_csv,
+                           xform: Replace::EmptyFieldValues,
+                           xformopt: {fields: %i[name sex],
+                                      value: 'NULL'})
+      expect(result).to eq(expected)
+    end
+  end
+
+    describe 'FieldValueWithStaticMapping' do
     test_csv = 'tmp/test.csv'
     mapping = {
       'm' => 'male',