diff --git a/.github/workflows/pull_request.yml b/.github/workflows/pull_request.yml
index ef356dae..e962a28d 100644
--- a/.github/workflows/pull_request.yml
+++ b/.github/workflows/pull_request.yml
@@ -50,7 +50,7 @@ jobs:
       - name: Install dependencies
         run: bundle install
       - name: Download test cases
-        run: git clone --depth 5 --branch v4.5.1 https://github.com/Unleash/client-specification.git client-specification
+        run: git clone --depth 5 --branch v5.0.2 https://github.com/Unleash/client-specification.git client-specification
       - name: Run tests
         run: bundle exec rake
         env:
diff --git a/README.md b/README.md
index c31712c2..8da1defe 100644
--- a/README.md
+++ b/README.md
@@ -528,7 +528,7 @@ You can also run `bin/console` for an interactive prompt that will allow you to
 This SDK is also built against the Unleash Client Specification tests.
 To run the Ruby SDK against this test suite, you'll need to have a copy on your machine, you can clone the repository directly using:
 
-`git clone --depth 5 --branch v4.5.1 https://github.com/Unleash/client-specification.git client-specification`
+`git clone --depth 5 --branch v5.0.2 https://github.com/Unleash/client-specification.git client-specification`
 
 After doing this, `rake spec` will also run the client specification tests.
 
diff --git a/lib/unleash/configuration.rb b/lib/unleash/configuration.rb
index 049d91a4..0ee344c4 100644
--- a/lib/unleash/configuration.rb
+++ b/lib/unleash/configuration.rb
@@ -53,7 +53,7 @@ def http_headers
       {
         'UNLEASH-INSTANCEID' => self.instance_id,
         'UNLEASH-APPNAME' => self.app_name,
-        'Unleash-Client-Spec' => '4.5.1'
+        'Unleash-Client-Spec' => '5.0.2'
       }.merge!(generate_custom_http_headers)
     end
 
diff --git a/lib/unleash/feature_toggle.rb b/lib/unleash/feature_toggle.rb
index 2ae0e214..151693b3 100644
--- a/lib/unleash/feature_toggle.rb
+++ b/lib/unleash/feature_toggle.rb
@@ -163,6 +163,7 @@ def variant_from_weights(context, stickiness, variant_definitions, group_id)
       variant_weight = Unleash::Strategy::Util.get_normalized_number(
         variant_salt(context, stickiness),
         group_id,
+        Unleash::Strategy::Util::VARIANT_NORMALIZER_SEED,
         sum_variant_defs_weights(variant_definitions)
       )
       prev_weights = 0
diff --git a/lib/unleash/strategy/flexible_rollout.rb b/lib/unleash/strategy/flexible_rollout.rb
index e6088984..e464d406 100644
--- a/lib/unleash/strategy/flexible_rollout.rb
+++ b/lib/unleash/strategy/flexible_rollout.rb
@@ -24,7 +24,7 @@ def is_enabled?(params = {}, context = nil)
         end
 
         group_id = params.fetch('groupId', '')
-        normalized_number = Util.get_normalized_number(stickiness_id, group_id)
+        normalized_number = Util.get_normalized_number(stickiness_id, group_id, 0)
 
         return false if stickiness_id.nil?
 
diff --git a/lib/unleash/strategy/gradual_rollout_sessionid.rb b/lib/unleash/strategy/gradual_rollout_sessionid.rb
index 0f2a553c..cdd175c4 100644
--- a/lib/unleash/strategy/gradual_rollout_sessionid.rb
+++ b/lib/unleash/strategy/gradual_rollout_sessionid.rb
@@ -14,7 +14,7 @@ def is_enabled?(params = {}, context = nil)
         return false if context.session_id.nil? || context.session_id.empty?
 
         percentage = Integer(params['percentage'] || 0)
-        (percentage.positive? && Util.get_normalized_number(context.session_id, params['groupId'] || "") <= percentage)
+        (percentage.positive? && Util.get_normalized_number(context.session_id, params['groupId'] || "", 0) <= percentage)
       end
     end
   end
diff --git a/lib/unleash/strategy/gradual_rollout_userid.rb b/lib/unleash/strategy/gradual_rollout_userid.rb
index 1aa3c052..13326649 100644
--- a/lib/unleash/strategy/gradual_rollout_userid.rb
+++ b/lib/unleash/strategy/gradual_rollout_userid.rb
@@ -14,7 +14,7 @@ def is_enabled?(params = {}, context = nil, _constraints = [])
         return false if context.user_id.nil? || context.user_id.empty?
 
         percentage = Integer(params['percentage'] || 0)
-        (percentage.positive? && Util.get_normalized_number(context.user_id, params['groupId'] || "") <= percentage)
+        (percentage.positive? && Util.get_normalized_number(context.user_id, params['groupId'] || "", 0) <= percentage)
       end
     end
   end
diff --git a/lib/unleash/strategy/util.rb b/lib/unleash/strategy/util.rb
index a00ade85..17b860b0 100644
--- a/lib/unleash/strategy/util.rb
+++ b/lib/unleash/strategy/util.rb
@@ -6,10 +6,11 @@ module Util
       module_function
 
       NORMALIZER = 100
+      VARIANT_NORMALIZER_SEED = 86028157;
 
       # convert the two strings () into a number between 1 and base (100 by default)
-      def get_normalized_number(identifier, group_id, base = NORMALIZER)
-        MurmurHash3::V32.str_hash("#{group_id}:#{identifier}") % base + 1
+      def get_normalized_number(identifier, group_id, seed, base = NORMALIZER)
+        MurmurHash3::V32.str_hash("#{group_id}:#{identifier}", seed) % base + 1
       end
     end
   end
diff --git a/spec/unleash/configuration_spec.rb b/spec/unleash/configuration_spec.rb
index dc379681..f5d0d5a9 100644
--- a/spec/unleash/configuration_spec.rb
+++ b/spec/unleash/configuration_spec.rb
@@ -146,7 +146,7 @@
           'X-API-KEY' => '123',
           'UNLEASH-APPNAME' => 'test-app',
           'UNLEASH-INSTANCEID' => config.instance_id,
-          'Unleash-Client-Spec' => '4.5.1'
+          'Unleash-Client-Spec' => '5.0.2'
         }
       )
       expect(custom_headers_proc).to have_received(:call).exactly(1).times
diff --git a/spec/unleash/feature_toggle_spec.rb b/spec/unleash/feature_toggle_spec.rb
index 7abc7adc..c0ee8e15 100644
--- a/spec/unleash/feature_toggle_spec.rb
+++ b/spec/unleash/feature_toggle_spec.rb
@@ -141,19 +141,19 @@
 
     let(:default_variant) { Unleash::Variant.new(name: 'unknown', default: true) }
 
-    it 'should return variant1 for user_id:1' do
+    it 'should return variant2 for user_id:1' do
       context = Unleash::Context.new(user_id: 10)
       expect(feature_toggle.get_variant(context, default_variant)).to have_attributes(
-        name: "variant1",
+        name: "variant2",
         enabled: true,
         payload: nil
       )
     end
 
-    it 'should return variant2 for user_id:2' do
+    it 'should return variant1 for user_id:2' do
       context = Unleash::Context.new(user_id: 2)
       expect(feature_toggle.get_variant(context, default_variant)).to have_attributes(
-        name: "variant2",
+        name: "variant1",
         enabled: true,
         payload: nil
       )
@@ -208,8 +208,8 @@
       )
     end
 
-    it 'should return variantB for user_id:2' do
-      context = Unleash::Context.new(user_id: 2)
+    it 'should return variantB for user_id:5' do
+      context = Unleash::Context.new(user_id: 5)
       expect(feature_toggle.get_variant(context, default_variant)).to have_attributes(
         name: "variantB",
         enabled: true,
@@ -285,7 +285,7 @@
             },
             "overrides" => [{
               "contextName" => "userId",
-              "values" => ["132", "61"]
+              "values" => ["133", "61"]
             }]
           },
           {
@@ -311,8 +311,8 @@
       )
     end
 
-    it 'should return variant1 for user_id:132 from override' do
-      context = Unleash::Context.new("userId" => 132)
+    it 'should return variant1 for user_id:133 from override' do
+      context = Unleash::Context.new("userId" => 133)
       expect(feature_toggle.get_variant(context)).to have_attributes(
         name: "variant1",
         enabled: true,
@@ -320,8 +320,8 @@
       )
     end
 
-    it 'should return variant2 for user_id:60' do
-      context = Unleash::Context.new(user_id: 60)
+    it 'should return variant2 for user_id:856' do
+      context = Unleash::Context.new(user_id: 856)
       expect(feature_toggle.get_variant(context)).to have_attributes(
         name: "variant2",
         enabled: true,
@@ -537,10 +537,10 @@
       )
     end
 
-    it 'should return variant1 organization 726' do
+    it 'should return variant1 organization 222' do
       context = Unleash::Context.new(
         properties: {
-          organization: '726'
+          organization: '222'
         }
       )
 
@@ -553,7 +553,7 @@
     it 'should return variant2 organization 48' do
       context = Unleash::Context.new(
         properties: {
-          organization: '48'
+          organization: '49'
         }
       )
 
@@ -563,10 +563,10 @@
       )
     end
 
-    it 'should return variant3 organization 381' do
+    it 'should return variant3 organization 726' do
       context = Unleash::Context.new(
         properties: {
-          organization: '381'
+          organization: '726'
         }
       )
 
@@ -576,10 +576,10 @@
       )
     end
 
-    it 'should return variant4 organization 222' do
+    it 'should return variant4 organization 381' do
       context = Unleash::Context.new(
         properties: {
-          organization: '222'
+          organization: '381'
         }
       )
 
diff --git a/spec/unleash/strategy/gradual_rollout_sessionid_spec.rb b/spec/unleash/strategy/gradual_rollout_sessionid_spec.rb
index b3d76f3f..d4412760 100644
--- a/spec/unleash/strategy/gradual_rollout_sessionid_spec.rb
+++ b/spec/unleash/strategy/gradual_rollout_sessionid_spec.rb
@@ -5,7 +5,7 @@
   describe '#is_enabled?' do
     let(:strategy) { Unleash::Strategy::GradualRolloutSessionId.new }
     let(:unleash_context) { Unleash::Context.new(session_id: 'secretsessionidhashgoeshere') }
-    let(:percentage) { Unleash::Strategy::Util.get_normalized_number(unleash_context.session_id, "") }
+    let(:percentage) { Unleash::Strategy::Util.get_normalized_number(unleash_context.session_id, "", 0) }
 
     it 'return true when percentage set is gt the number returned by the hash function' do
       expect(strategy.is_enabled?({ 'percentage' => (percentage + 1).to_s }, unleash_context)).to be_truthy
diff --git a/spec/unleash/strategy/gradual_rollout_userid_spec.rb b/spec/unleash/strategy/gradual_rollout_userid_spec.rb
index 2ed96134..d0318d2b 100644
--- a/spec/unleash/strategy/gradual_rollout_userid_spec.rb
+++ b/spec/unleash/strategy/gradual_rollout_userid_spec.rb
@@ -4,7 +4,7 @@
   describe '#is_enabled?' do
     let(:strategy) { Unleash::Strategy::GradualRolloutUserId.new }
     let(:unleash_context) { Unleash::Context.new({ 'userId' => 'alice' }) }
-    let(:percentage) { Unleash::Strategy::Util.get_normalized_number(unleash_context.user_id, "") }
+    let(:percentage) { Unleash::Strategy::Util.get_normalized_number(unleash_context.user_id, "", 0) }
 
     it 'return true when percentage set is gt the number returned by the hash function' do
       expect(strategy.is_enabled?({ 'percentage' => (percentage + 1).to_s }, unleash_context)).to be_truthy
diff --git a/spec/unleash/strategy/util_spec.rb b/spec/unleash/strategy/util_spec.rb
index 234b160c..bf5ab3b0 100644
--- a/spec/unleash/strategy/util_spec.rb
+++ b/spec/unleash/strategy/util_spec.rb
@@ -3,8 +3,8 @@
 RSpec.describe Unleash::Strategy::Util do
   describe '.get_normalized_number' do
     it "returns correct values" do
-      expect(Unleash::Strategy::Util.get_normalized_number('123', 'gr1')).to eq(73)
-      expect(Unleash::Strategy::Util.get_normalized_number('999', 'groupX')).to eq(25)
+      expect(Unleash::Strategy::Util.get_normalized_number('123', 'gr1', 0)).to eq(73)
+      expect(Unleash::Strategy::Util.get_normalized_number('999', 'groupX', 0)).to eq(25)
     end
   end
 end