diff --git a/spec/ajax-datatables-rails/datatable/simple_order_spec.rb b/spec/ajax-datatables-rails/datatable/simple_order_spec.rb
index cae8e37c..28f20058 100644
--- a/spec/ajax-datatables-rails/datatable/simple_order_spec.rb
+++ b/spec/ajax-datatables-rails/datatable/simple_order_spec.rb
@@ -18,6 +18,8 @@
       after  { AjaxDatatablesRails.config.nulls_last = false }
 
       it 'sql query' do
+        skip('unsupported database adapter') if ENV['DB_ADAPTER'] == 'oracle_enhanced'
+
         expect(simple_order.query('email')).to eq(
           "email DESC #{nulls_last_sql}"
         )
diff --git a/spec/ajax-datatables-rails/orm/active_record_filter_records_spec.rb b/spec/ajax-datatables-rails/orm/active_record_filter_records_spec.rb
index b55b770b..a15202b4 100644
--- a/spec/ajax-datatables-rails/orm/active_record_filter_records_spec.rb
+++ b/spec/ajax-datatables-rails/orm/active_record_filter_records_spec.rb
@@ -126,7 +126,7 @@
         expect(result).to be_a(Arel::Nodes::And)
       end
 
-      if AjaxDatatablesRails.config.db_adapter == :postgresql
+      if ENV['DB_ADAPTER'] == 'postgresql'
         context 'when db_adapter is postgresql' do
           it 'can call #to_sql on returned object' do
             result = datatable.build_conditions_for_selected_columns
@@ -138,7 +138,7 @@
         end
       end
 
-      if AjaxDatatablesRails.config.db_adapter.in? %i[oracle oracleenhanced]
+      if ENV['DB_ADAPTER'] == 'oracle_enhanced'
         context 'when db_adapter is oracle' do
           it 'can call #to_sql on returned object' do
             result = datatable.build_conditions_for_selected_columns
@@ -150,7 +150,7 @@
         end
       end
 
-      if AjaxDatatablesRails.config.db_adapter.in? %i[mysql2 sqlite3]
+      if ENV['DB_ADAPTER'] == 'mysql2'
         context 'when db_adapter is mysql2' do
           it 'can call #to_sql on returned object' do
             result = datatable.build_conditions_for_selected_columns
@@ -288,7 +288,7 @@
         create(:user, last_name: 'MARY')
       end
 
-      if AjaxDatatablesRails.config.db_adapter == :oracleenhanced
+      if ENV['DB_ADAPTER'] == 'oracle_enhanced'
         context 'when db_adapter is oracleenhanced' do
           it 'should filter records matching' do
             datatable.params[:columns]['3'][:search][:value] = 'RY'
diff --git a/spec/ajax-datatables-rails/orm/active_record_paginate_records_spec.rb b/spec/ajax-datatables-rails/orm/active_record_paginate_records_spec.rb
index d4964178..51689833 100644
--- a/spec/ajax-datatables-rails/orm/active_record_paginate_records_spec.rb
+++ b/spec/ajax-datatables-rails/orm/active_record_paginate_records_spec.rb
@@ -16,8 +16,8 @@
     end
 
     it 'paginates records properly' do
-      if AjaxDatatablesRails.config.db_adapter.in? %i[oracle oracleenhanced]
-        if Rails.version.in? %w[4.0.13 4.1.16 4.2.10]
+      if ENV['DB_ADAPTER'] == 'oracle_enhanced'
+        if Rails.version.in? %w[4.2.11]
           expect(datatable.paginate_records(records).to_sql).to include(
             'rownum <= 10'
           )
@@ -34,8 +34,8 @@
 
       datatable.params[:start] = '26'
       datatable.params[:length] = '25'
-      if AjaxDatatablesRails.config.db_adapter.in? %i[oracle oracleenhanced]
-        if Rails.version.in? %w[4.0.13 4.1.16 4.2.10]
+      if ENV['DB_ADAPTER'] == 'oracle_enhanced'
+        if Rails.version.in? %w[4.2.11]
           expect(datatable.paginate_records(records).to_sql).to include(
             'rownum <= 51'
           )
diff --git a/spec/ajax-datatables-rails/orm/active_record_sort_records_spec.rb b/spec/ajax-datatables-rails/orm/active_record_sort_records_spec.rb
index ba74fe01..1c0e8cad 100644
--- a/spec/ajax-datatables-rails/orm/active_record_sort_records_spec.rb
+++ b/spec/ajax-datatables-rails/orm/active_record_sort_records_spec.rb
@@ -49,6 +49,8 @@
     after  { AjaxDatatablesRails.config.nulls_last = false }
 
     it 'can handle multiple sorting columns' do
+      skip('unsupported database adapter') if ENV['DB_ADAPTER'] == 'oracle_enhanced'
+
       # set to order by Users username in ascending order, and
       # by Users email in descending order
       datatable.params[:order]['0'] = { column: '0', dir: 'asc' }
@@ -61,6 +63,8 @@
 
   describe '#sort_records with nulls last using column config' do
     it 'can handle multiple sorting columns' do
+      skip('unsupported database adapter') if ENV['DB_ADAPTER'] == 'oracle_enhanced'
+
       # set to order by Users username in ascending order, and
       # by Users email in descending order
       nulls_last_datatable.params[:order]['0'] = { column: '0', dir: 'asc' }