diff --git a/spec/acceptance/realtime/connection_failures_spec.rb b/spec/acceptance/realtime/connection_failures_spec.rb
index 21f74b230..3717f6807 100644
--- a/spec/acceptance/realtime/connection_failures_spec.rb
+++ b/spec/acceptance/realtime/connection_failures_spec.rb
@@ -1486,7 +1486,7 @@ def kill_connection_transport_and_prevent_valid_resume
       end
 
       context 'with non-production environment' do
-        let(:environment)    { 'sandbox' }
+        let(:environment)    { 'lmars-dev' }
         let(:expected_host)  { "#{environment}-#{Ably::Realtime::Client::DOMAIN}" }
         let(:client_options) { timeout_options.merge(environment: environment) }
 
diff --git a/spec/acceptance/rest/client_spec.rb b/spec/acceptance/rest/client_spec.rb
index db80bb65f..fbe16d75b 100644
--- a/spec/acceptance/rest/client_spec.rb
+++ b/spec/acceptance/rest/client_spec.rb
@@ -312,7 +312,7 @@ def encode64(text)
 
       context 'when environment is NOT production (#RSC15b)' do
         context 'and custom fallback hosts are empty' do
-          let(:client_options) { default_options.merge(environment: 'sandbox', key: api_key, fallback_hosts: []) }
+          let(:client_options) { default_options.merge(environment: 'lmars-dev', key: api_key, fallback_hosts: []) }
           let!(:default_host_request_stub) do
             stub_request(:post, "https://#{environment}-#{Ably::Rest::Client::DOMAIN}#{path}").to_return do
               raise Faraday::TimeoutError.new('timeout error message')
@@ -325,14 +325,14 @@ def encode64(text)
         end
 
         context 'and no custom fallback hosts are provided' do
-          let(:client_options) { default_options.merge(environment: 'sandbox', key: api_key) }
+          let(:client_options) { default_options.merge(environment: 'lmars-dev', key: api_key) }
 
-          it 'should make connection attempts to sandbox-a-fallback.ably-realtime.com, sandbox-b-fallback.ably-realtime.com, sandbox-c-fallback.ably-realtime.com, sandbox-d-fallback.ably-realtime.com, sandbox-e-fallback.ably-realtime.com (#RSC15a)' do
+          it 'should make connection attempts to lmars-dev-a-fallback.ably-realtime.com, lmars-dev-b-fallback.ably-realtime.com, lmars-dev-c-fallback.ably-realtime.com, lmars-dev-d-fallback.ably-realtime.com, lmars-dev-e-fallback.ably-realtime.com (#RSC15a)' do
             hosts = []
             5.times do
               hosts << client.fallback_connection.host
             end
-            expect(hosts).to match_array(%w(a b c d e).map { |id| "sandbox-#{id}-fallback.ably-realtime.com" })
+            expect(hosts).to match_array(%w(a b c d e).map { |id| "lmars-dev-#{id}-fallback.ably-realtime.com" })
           end
         end
       end
diff --git a/spec/rspec_config.rb b/spec/rspec_config.rb
index c299da4af..b3c92ffbc 100644
--- a/spec/rspec_config.rb
+++ b/spec/rspec_config.rb
@@ -35,7 +35,7 @@
       key_name: 'app_id.key_name',
       key_secret: 'secret',
       api_key: 'app_id.key_name:secret',
-      environment: 'sandbox'
+      environment: 'lmars-dev'
     ))
     WebMock.enable!
   end
diff --git a/spec/shared/client_initializer_behaviour.rb b/spec/shared/client_initializer_behaviour.rb
index 5ccfbeb22..f7471f839 100644
--- a/spec/shared/client_initializer_behaviour.rb
+++ b/spec/shared/client_initializer_behaviour.rb
@@ -164,10 +164,10 @@ def rest?
       end
 
       context 'with environment option' do
-        let(:client_options) { default_options.merge(environment: 'sandbox', auto_connect: false) }
+        let(:client_options) { default_options.merge(environment: 'lmars-dev', auto_connect: false) }
 
         it 'uses an alternate endpoint' do
-          expect(subject.endpoint.to_s).to eql("#{protocol}s://sandbox-#{subdomain}.ably.io")
+          expect(subject.endpoint.to_s).to eql("#{protocol}s://lmars-dev-#{subdomain}.ably.io")
         end
       end
 
diff --git a/spec/support/test_app.rb b/spec/support/test_app.rb
index 2e7fc3944..79986d363 100644
--- a/spec/support/test_app.rb
+++ b/spec/support/test_app.rb
@@ -66,7 +66,7 @@ def delete
   end
 
   def environment
-    ENV['ABLY_ENV'] || 'sandbox'
+    ENV['ABLY_ENV'] || 'lmars-dev'
   end
 
   def create_test_app