diff --git a/.ruby-version.example b/.ruby-version.example
index da6b0a8f16..338a5b5d8f 100644
--- a/.ruby-version.example
+++ b/.ruby-version.example
@@ -1 +1 @@
-2.5.6
+2.6.6
diff --git a/Gemfile.lock b/Gemfile.lock
index 07dcb58050..5f1bcab939 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -394,9 +394,10 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2020.0512)
-    mimemagic (0.3.5)
+    mimemagic (0.3.7)
+      nokogiri (~> 1.11.2)
     mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.5.0)
     minitest (5.14.2)
     multi_json (1.13.1)
     multi_xml (0.6.0)
@@ -413,8 +414,9 @@ GEM
     net-sftp (2.1.2)
       net-ssh (>= 2.6.5)
     net-ssh (6.1.0)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
+    nokogiri (1.11.2)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
     open4 (1.3.4)
     orm_adapter (0.5.0)
     pandoc-ruby (2.0.2)
@@ -443,6 +445,7 @@ GEM
     public_suffix (3.1.1)
     pundit (2.0.1)
       activesupport (>= 3.0.0)
+    racc (1.5.2)
     rack (1.6.13)
     rack-accept (0.4.5)
       rack (>= 0.4)
diff --git a/spec/features/reaction_equiv_spec.rb b/spec/features/reaction_equiv_spec.rb
index 21b1109b73..405fabe932 100644
--- a/spec/features/reaction_equiv_spec.rb
+++ b/spec/features/reaction_equiv_spec.rb
@@ -28,7 +28,7 @@
   let!(:mr2) { create(:molecule, molecular_weight: 330.2360496) }
 
   let(:material) { create(:sample, name: 'Material', target_amount_value: 7.15, collections: user.collections, molecule: m1) }
-  let(:reactant1) { create(:sample, name: 'Reactant1', target_amount_value: 5.435, collections: user.collections) }
+  let(:reactant1) { create(:sample, name: 'Reactant1', target_amount_value: 7.15, collections: user.collections, molecule: m1) }
   let(:reactant2) { create(:sample, name: 'Reactant2', target_amount_value: 3.123, collections: user.collections) }
   let(:solvent) { create(:sample, name: 'Solvent', collections: user.collections) }
   let(:product) { create(:sample, name: 'Product', real_amount_value: 4.671, collections: user.collections, molecule: m2) }
@@ -65,7 +65,7 @@
     end
 
     it 'change material amount', js: true do
-      material_new_amount = 5000
+      material_new_amount = 4000
       find('.tree-view', text: 'chemotion.net').click
       first('i.icon-reaction').click
       first('i.c-bs-success').click
@@ -81,7 +81,7 @@
       material_field.click
       reactants_field.click
       reactants_new_amount = reactants_field.value.to_i
-      expect_result = material_new_amount / material.molecule.molecular_weight * 2
+      expect_result = material_new_amount / material.molecule.molecular_weight
       expect_result *= reactant1.molecule.molecular_weight
       expect(reactants_new_amount).to eq(expect_result.to_i)
     end