diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index 9d6b8c4af..bac034c13 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -62,6 +62,8 @@ RSpec.describe ApplicationHelper, type: :helper do
   end
 
   describe "#release_adjusted_cache_key" do
+    after { ForemInstance.instance_variable_set(:@deployed_at, nil) }
+
     it "does nothing when RELEASE_FOOTPRINT is not set" do
       allow(ApplicationConfig).to receive(:[]).with("RELEASE_FOOTPRINT").and_return(nil)
       expect(helper.release_adjusted_cache_key("cache-me")).to include("cache-me")
diff --git a/spec/models/forem_instance_spec.rb b/spec/models/forem_instance_spec.rb
index 5bda32756..e947fe608 100644
--- a/spec/models/forem_instance_spec.rb
+++ b/spec/models/forem_instance_spec.rb
@@ -2,19 +2,20 @@ require "rails_helper"
 
 RSpec.describe ForemInstance, type: :model do
   describe "deployed_at" do
-    before do
+    before { allow(ENV).to receive(:[]) }
+
+    after do
       described_class.instance_variable_set(:@deployed_at, nil)
     end
 
     it "sets the RELEASE_FOOTPRINT if present" do
       allow(ApplicationConfig).to receive(:[]).with("RELEASE_FOOTPRINT").and_return("A deploy date")
-      stub_const("ENV", ENV.to_h.merge("HEROKU_RELEASE_CREATED_AT" => ""))
       expect(described_class.deployed_at).to eq(ApplicationConfig["RELEASE_FOOTPRINT"])
     end
 
     it "sets the HEROKU_RELEASE_CREATED_AT if the RELEASE_FOOTPRINT is not present" do
       allow(ApplicationConfig).to receive(:[]).with("RELEASE_FOOTPRINT").and_return("")
-      stub_const("ENV", ENV.to_h.merge("HEROKU_RELEASE_CREATED_AT" => "A deploy date set on Heroku"))
+      allow(ENV).to receive(:[]).with("HEROKU_RELEASE_CREATED_AT").and_return("A deploy date set on Heroku")
       expect(described_class.deployed_at).to eq(ENV["HEROKU_RELEASE_CREATED_AT"])
     end
   end
diff --git a/spec/requests/admin/admin_portals_spec.rb b/spec/requests/admin/admin_portals_spec.rb
index 0dc8ff394..cbbdfe83f 100644
--- a/spec/requests/admin/admin_portals_spec.rb
+++ b/spec/requests/admin/admin_portals_spec.rb
@@ -24,6 +24,10 @@ RSpec.describe "/admin", type: :request do
   end
 
   describe "Last deployed and Lastest Commit ID card" do
+    after do
+      ForemInstance.instance_variable_set(:@deployed_at, nil)
+    end
+
     it "shows 'Not Available' if the Last deployed time is missing" do
       stub_const("ENV", ENV.to_h.merge("HEROKU_RELEASE_CREATED_AT" => ""))
 
@@ -34,7 +38,6 @@ RSpec.describe "/admin", type: :request do
 
     it "shows the correct value if the Last deployed time is available" do
       stub_const("ENV", ENV.to_h.merge("HEROKU_RELEASE_CREATED_AT" => "Some date"))
-      ForemInstance.instance_variable_set(:@deployed_at, nil)
 
       get admin_path