diff --git a/spec/controllers/admin_public_body_controller_spec.rb b/spec/controllers/admin_public_body_controller_spec.rb
index 676cb19617..ac5c5288fe 100644
--- a/spec/controllers/admin_public_body_controller_spec.rb
+++ b/spec/controllers/admin_public_body_controller_spec.rb
@@ -753,21 +753,18 @@
 
   describe "when administering public bodies and paying attention to authentication" do
     before do
-      config = MySociety::Config.load_default
-      config['SKIP_ADMIN_AUTH'] = false
+      allow(AlaveteliConfiguration).to receive(:skip_admin_auth).
+        and_return(false)
       basic_auth_login @request
     end
 
-    after do
-      config = MySociety::Config.load_default
-      config['SKIP_ADMIN_AUTH'] = true
-    end
-
     def setup_emergency_credentials(username, password)
-      config = MySociety::Config.load_default
-      config['SKIP_ADMIN_AUTH'] = false
-      config['ADMIN_USERNAME'] = username
-      config['ADMIN_PASSWORD'] = password
+      allow(AlaveteliConfiguration).to receive(:skip_admin_auth).
+        and_return(false)
+      allow(AlaveteliConfiguration).to receive(:admin_username).
+        and_return(username)
+      allow(AlaveteliConfiguration).to receive(:admin_password).
+        and_return(password)
       @request.env["HTTP_AUTHORIZATION"] = ""
     end
 
@@ -782,8 +779,8 @@ def setup_emergency_credentials(username, password)
     end
 
     it "skips admin authorisation when SKIP_ADMIN_AUTH set" do
-      config = MySociety::Config.load_default
-      config['SKIP_ADMIN_AUTH'] = true
+      allow(AlaveteliConfiguration).to receive(:skip_admin_auth).
+        and_return(true)
       @request.env["HTTP_AUTHORIZATION"] = ""
       n = PublicBody.count
       post :destroy, params: { id: public_bodies(:forlorn_public_body).id }
@@ -871,8 +868,8 @@ def setup_emergency_credentials(username, password)
       end
 
       it 'returns the REMOTE_USER value from the request environment when skipping admin auth' do
-        config = MySociety::Config.load_default
-        config['SKIP_ADMIN_AUTH'] = true
+        allow(AlaveteliConfiguration).to receive(:skip_admin_auth).
+          and_return(true)
         @request.env["HTTP_AUTHORIZATION"] = ""
         @request.env["REMOTE_USER"] = "i_am_admin"
         post :show, params: { id: public_bodies(:humpadink_public_body).id }
diff --git a/spec/controllers/general_controller_spec.rb b/spec/controllers/general_controller_spec.rb
index 42f209b7cc..24362bd10d 100644
--- a/spec/controllers/general_controller_spec.rb
+++ b/spec/controllers/general_controller_spec.rb
@@ -115,8 +115,8 @@
   end
 
   it "should render the front page with default language and ignore the browser setting" do
-    config = MySociety::Config.load_default
-    config['USE_DEFAULT_BROWSER_LANGUAGE'] = false
+    allow(AlaveteliConfiguration).to receive(:use_default_browser_language).
+      and_return(false)
     accept_language = "en-GB,en-US;q=0.8,en;q=0.6"
     request.env['HTTP_ACCEPT_LANGUAGE'] = accept_language
     with_default_locale("es") do
@@ -126,8 +126,8 @@
   end
 
   it "should render the front page with browser-selected language when there's no default set" do
-    config = MySociety::Config.load_default
-    config['USE_DEFAULT_BROWSER_LANGUAGE'] = true
+    allow(AlaveteliConfiguration).to receive(:use_default_browser_language).
+      and_return(true)
     accept_language = "es-ES,en-GB,en-US;q=0.8,en;q=0.6"
     request.env['HTTP_ACCEPT_LANGUAGE'] = accept_language
     get :frontpage
diff --git a/spec/integration/statistics_spec.rb b/spec/integration/statistics_spec.rb
index 38ad50ee08..e85eed7140 100644
--- a/spec/integration/statistics_spec.rb
+++ b/spec/integration/statistics_spec.rb
@@ -2,9 +2,10 @@
 
 RSpec.describe "Site statistics" do
   before :each do
-    config = MySociety::Config.load_default
-    config['MINIMUM_REQUESTS_FOR_STATISTICS'] = 1
-    config['PUBLIC_BODY_STATISTICS_PAGE'] = true
+    allow(AlaveteliConfiguration).to receive(:minimum_requests_for_statistics).
+      and_return(1)
+    allow(AlaveteliConfiguration).to receive(:public_body_statistics_page).
+      and_return(true)
   end
 
   describe "for public bodies" do
diff --git a/spec/lib/alaveteli_text_masker_spec.rb b/spec/lib/alaveteli_text_masker_spec.rb
index 376c7f5a9c..c0efa7a4cf 100644
--- a/spec/lib/alaveteli_text_masker_spec.rb
+++ b/spec/lib/alaveteli_text_masker_spec.rb
@@ -86,9 +86,8 @@
 
     context 'applying masks to PDF' do
       def pdf_replacement_test(use_ghostscript_compression)
-        config = MySociety::Config.load_default
-        previous = config['USE_GHOSTSCRIPT_COMPRESSION']
-        config['USE_GHOSTSCRIPT_COMPRESSION'] = use_ghostscript_compression
+        allow(AlaveteliConfiguration).to receive(:use_ghostscript_compression).
+          and_return(use_ghostscript_compression)
         orig_pdf = load_file_fixture('tfl.pdf')
         pdf = orig_pdf.dup
 
@@ -100,7 +99,6 @@ def pdf_replacement_test(use_ghostscript_compression)
         masked_text = MailHandler.get_attachment_text_one_file('application/pdf', result)
         expect(masked_text).not_to match(/foi@tfl.gov.uk/)
         expect(masked_text).to match(/xxx@xxx.xxx.xx/)
-        config['USE_GHOSTSCRIPT_COMPRESSION'] = previous
       end
 
       it "replaces everything in PDF files using pdftk" do