diff --git a/app/models/environment.rb b/app/models/environment.rb
index 9b05f8b1cd5fa8d3a72e6de7d74536cfb4283ee4..44e39e2144281af704f4f48d5862ed999dd5814e 100644
--- a/app/models/environment.rb
+++ b/app/models/environment.rb
@@ -6,7 +6,10 @@ class Environment < ActiveRecord::Base
 
   belongs_to :project, required: true, validate: true
 
-  has_many :deployments, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
+  has_many :deployments,
+    -> (env) { where(project_id: env.project_id) },
+    dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
+
   has_one :last_deployment, -> { order('deployments.id DESC') }, class_name: 'Deployment'
 
   before_validation :nullify_external_url
diff --git a/changelogs/unreleased/ci-environment-status-performance.yml b/changelogs/unreleased/ci-environment-status-performance.yml
new file mode 100644
index 0000000000000000000000000000000000000000..8812733b5a786155c2acf984aea27c40782e548e
--- /dev/null
+++ b/changelogs/unreleased/ci-environment-status-performance.yml
@@ -0,0 +1,5 @@
+---
+title: Constrain environment deployments to project IDs
+merge_request:
+author:
+type: other