diff --git a/lib/shoulda/matchers/active_model/validate_numericality_of_matcher.rb b/lib/shoulda/matchers/active_model/validate_numericality_of_matcher.rb
index 8d2f85ea..9d3d0f78 100644
--- a/lib/shoulda/matchers/active_model/validate_numericality_of_matcher.rb
+++ b/lib/shoulda/matchers/active_model/validate_numericality_of_matcher.rb
@@ -432,7 +432,7 @@ module Shoulda
         end
 
         def given_numeric_column?
-          [:integer, :float].include?(column_type)
+          [:integer, :float, :decimal].include?(column_type)
         end
 
         private
diff --git a/spec/unit/shoulda/matchers/active_model/validate_numericality_of_matcher_spec.rb b/spec/unit/shoulda/matchers/active_model/validate_numericality_of_matcher_spec.rb
index 3ef09039..31d2d8af 100644
--- a/spec/unit/shoulda/matchers/active_model/validate_numericality_of_matcher_spec.rb
+++ b/spec/unit/shoulda/matchers/active_model/validate_numericality_of_matcher_spec.rb
@@ -150,6 +150,18 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
             to raise_error(described_class::IneffectiveTestError)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'raises an IneffectiveTestError' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+          )
+          assertion = -> { expect(record).to validate_numericality }
+
+          expect(&assertion).
+            to raise_error(described_class::IneffectiveTestError)
+        end
+      end
     end
 
     context 'and not validating anything' do
@@ -233,6 +245,17 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
           expect(record).to validate_numericality.odd
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            odd: true,
+          )
+
+          expect(record).to validate_numericality.odd
+        end
+      end
     end
 
     context 'and not validating with odd' do
@@ -276,6 +299,17 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
           expect(record).to validate_numericality.even
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            even: true,
+          )
+
+          expect(record).to validate_numericality.even
+        end
+      end
     end
 
     context 'and not validating with even' do
@@ -319,6 +353,17 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
           expect(record).to validate_numericality.is_less_than_or_equal_to(18)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            less_than_or_equal_to: 18,
+          )
+
+          expect(record).to validate_numericality.is_less_than_or_equal_to(18)
+        end
+      end
     end
 
     context 'and not validating with less_than_or_equal_to' do
@@ -366,6 +411,17 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
           expect(record).to validate_numericality.is_less_than(18)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            less_than: 18,
+          )
+
+          expect(record).to validate_numericality.is_less_than(18)
+        end
+      end
     end
 
     context 'and not validating with less_than' do
@@ -411,6 +467,17 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
           expect(record).to validate_numericality.is_equal_to(18)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            equal_to: 18,
+          )
+
+          expect(record).to validate_numericality.is_equal_to(18)
+        end
+      end
     end
 
     context 'and not validating with equal_to' do
@@ -462,6 +529,19 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
             is_greater_than_or_equal_to(18)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            greater_than_or_equal_to: 18,
+          )
+
+          expect(record).
+            to validate_numericality.
+            is_greater_than_or_equal_to(18)
+        end
+      end
     end
 
     context 'not validating with greater_than_or_equal_to' do
@@ -513,6 +593,19 @@ describe Shoulda::Matchers::ActiveModel::ValidateNumericalityOfMatcher, type: :m
             is_greater_than(18)
         end
       end
+
+      context 'when the column is a decimal column' do
+        it 'accepts (and does not raise an error)' do
+          record = build_record_validating_numericality(
+            column_type: :decimal,
+            greater_than: 18,
+          )
+
+          expect(record).
+            to validate_numericality.
+            is_greater_than(18)
+        end
+      end
     end
 
     context 'and not validating with greater_than' do