diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd88843..b4f2e4f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ### 4.1.1 (Next)
 
+* [#239](https://github.com/mongoid/mongoid-rspec/pull/239): Add support for if/unless validator options - [@knovoselic](https://github.com/knovoselic).
 * Your contribution here.
 
 ### 4.1.0 (6/12/2020)
diff --git a/README.md b/README.md
index ffd5514..d7b9c5d 100644
--- a/README.md
+++ b/README.md
@@ -315,6 +315,22 @@ RSpec.describe Person do
    # should redefine the kind method to return :custom, i.e. "def self.kind() :custom end"
   it { is_expected.to custom_validate(:ssn).with_validator(SsnValidator) }
 end
+
+# If you're using validators with if/unless conditionals, spec subject must be object instance
+# This is supported on Mongoid 4 and newer
+Rspec.describe User do
+  context 'when user has `admin` role' do
+    subject { User.new(role: 'admin') }
+
+    it { is_expected.to validate_length_of(:password).greater_than(20) }
+  end
+
+  context 'when user does not have `admin` role' do
+    subject { User.new(role: 'member') }
+
+    it { is_expected.not_to validate_length_of(:password) }
+  end
+end
 ```
 
 ### Mass Assignment Matcher
diff --git a/lib/matchers/validations.rb b/lib/matchers/validations.rb
index e3959fb..9a0a334 100644
--- a/lib/matchers/validations.rb
+++ b/lib/matchers/validations.rb
@@ -12,7 +12,8 @@ def matches?(actual)
           @klass = actual.is_a?(Class) ? actual : actual.class
 
           @validator = @klass.validators_on(@field).detect do |v|
-            (v.kind.to_s == @type) && (!v.options[:on] || on_options_matches?(v))
+            (v.kind.to_s == @type) && (!v.options[:on] || on_options_matches?(v)) &&
+              if_condition_matches?(actual, v) && unless_condition_matches?(actual, v)
           end
 
           if @validator
@@ -59,6 +60,31 @@ def with_message(message)
 
         private
 
+        def if_condition_matches?(actual, validator)
+          return true unless validator.options[:if]
+
+          check_condition actual, validator.options[:if]
+        end
+
+        def unless_condition_matches?(actual, validator)
+          return true unless validator.options[:unless]
+
+          !check_condition actual, validator.options[:unless]
+        end
+
+        def check_condition(actual, filter)
+          raise ArgumentError, 'Spec subject must be object instance when testing validators with if/unless condition.' if actual.is_a?(Class)
+
+          case filter
+          when Symbol
+            actual.send filter
+          when ::Proc
+            actual.instance_exec(&filter)
+          else
+            raise ArgumentError, "Unexpected filter: #{filter.inspect}"
+          end
+        end
+
         def check_on
           validator_on_methods = [@validator.options[:on]].flatten
 
diff --git a/spec/models/article.rb b/spec/models/article.rb
index b2959ac..ee64dd1 100644
--- a/spec/models/article.rb
+++ b/spec/models/article.rb
@@ -9,6 +9,7 @@ class Article
   field :number_of_comments, type: Integer
   field :status, type: Symbol
   field :deletion_date, type: DateTime, default: nil
+  field :reviewer, type: String, default: nil
 
   embeds_many :comments, cascade_callbacks: true, inverse_of: :article
   embeds_one :permalink, inverse_of: :linkable
@@ -24,6 +25,10 @@ class Article
 
   validates_absence_of :deletion_date if Mongoid::Compatibility::Version.mongoid4_or_newer?
 
+  validates_presence_of :reviewer, unless: -> { status == :pending }
+
+  validates_absence_of :comments, unless: :allow_comments if Mongoid::Compatibility::Version.mongoid4_or_newer?
+
   index({ title: 1 }, unique: true, background: true, drop_dups: true)
   index(published: 1)
   index('permalink._id' => 1)
diff --git a/spec/models/user.rb b/spec/models/user.rb
index 101991e..670c261 100644
--- a/spec/models/user.rb
+++ b/spec/models/user.rb
@@ -30,9 +30,17 @@ class User
   validates :provider_uid, presence: true
   validates :locale, inclusion: { in: ->(_user) { %i[en ru] } }
 
+  with_options if: :admin? do
+    validates :password, length: { minimum: 20 }
+  end
+
+  with_options if: -> { role == 'moderator' } do
+    validates :password, length: { minimum: 10 }
+  end
+
   accepts_nested_attributes_for :articles, :comments
 
   def admin?
-    false
+    role == 'admin'
   end
 end
diff --git a/spec/unit/validations_spec.rb b/spec/unit/validations_spec.rb
index 79f2cd3..e0648ea 100644
--- a/spec/unit/validations_spec.rb
+++ b/spec/unit/validations_spec.rb
@@ -59,3 +59,63 @@
     it { is_expected.to validate_format_of(:to).with_message('format') }
   end
 end
+
+if Mongoid::Compatibility::Version.mongoid4_or_newer?
+  RSpec.describe 'Conditional validations' do
+    describe 'validations with if condition using symbol' do
+      context 'when the condition is met' do
+        subject { User.new(role: 'admin') }
+
+        it { is_expected.to validate_length_of(:password).greater_than(20) }
+      end
+
+      context 'when the condition is not met' do
+        subject { User.new(role: 'member') }
+
+        it { is_expected.not_to validate_length_of(:password) }
+      end
+    end
+
+    describe 'validations with if condition using lambda' do
+      context 'when the condition is met' do
+        subject { User.new(role: 'moderator') }
+
+        it { is_expected.to validate_length_of(:password).greater_than(10) }
+      end
+
+      context 'when the condition is not met' do
+        subject { User.new(role: 'member') }
+
+        it { is_expected.not_to validate_length_of(:password) }
+      end
+    end
+
+    describe 'validations with unless condition using symbol' do
+      context 'when the condition is met' do
+        subject { Article.new(allow_comments: false) }
+
+        it { is_expected.to validate_absence_of(:comments) }
+      end
+
+      context 'when the condition is not met' do
+        subject { Article.new(allow_comments: true) }
+
+        it { is_expected.not_to validate_absence_of(:comments) }
+      end
+    end
+
+    describe 'validations with unless condition using lambda' do
+      context 'when the condition is met' do
+        subject { Article.new(status: :rejected) }
+
+        it { is_expected.to validate_presence_of(:reviewer) }
+      end
+
+      context 'when the condition is not met' do
+        subject { Article.new(status: :pending) }
+
+        it { is_expected.not_to validate_presence_of(:reviewer) }
+      end
+    end
+  end
+end