diff --git a/.github/workflows/test_js.yml b/.github/workflows/test_js.yml
index c92f4780e..e3f0e8fb3 100644
--- a/.github/workflows/test_js.yml
+++ b/.github/workflows/test_js.yml
@@ -1,6 +1,7 @@
 name: Javascript testing
 
 on:
+  # Warning: changing run conditions could prevent coverage report in PR, see codecov.yml for `after_n_builds`
   - push
   - pull_request
 
diff --git a/.github/workflows/test_ruby.yml b/.github/workflows/test_ruby.yml
index cbc21de01..678e80995 100644
--- a/.github/workflows/test_ruby.yml
+++ b/.github/workflows/test_ruby.yml
@@ -1,6 +1,7 @@
 name: Ruby RSpec Tests
 
 on:
+  # Warning: changing run conditions could prevent coverage report in PR, see codecov.yml for `after_n_builds`
   - push
   - pull_request
 
diff --git a/codecov.yml b/codecov.yml
index 059588a88..5ff6b9de0 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -1,2 +1,6 @@
 ignore:
   - '**/*.vue' # ignore all .vue files - TODO: remove this after Vue SFC is supported (see https://github.com/sanger/limber/pull/1585)
+codecov:
+  notify:
+    # do not notify until at least n builds have been uploaded from the CI pipeline
+    after_n_builds: 4 # js_test (push), js_test (pull_request), ruby_test (push), ruby_test (pull_request)