diff --git a/argocd/structure_metadata.go b/argocd/structure_metadata.go
index b3cda13e..2ccbf566 100644
--- a/argocd/structure_metadata.go
+++ b/argocd/structure_metadata.go
@@ -59,5 +59,8 @@ func metadataIsInternalKey(annotationKey string) bool {
 	if err == nil && strings.HasSuffix(u.Hostname(), "kubernetes.io") {
 		return true
 	}
+	if err == nil && annotationKey == "notified.notifications.argoproj.io" {
+		return true
+	}
 	return false
 }
diff --git a/argocd/structure_metadata_test.go b/argocd/structure_metadata_test.go
index e4a1c4c0..2b255708 100644
--- a/argocd/structure_metadata_test.go
+++ b/argocd/structure_metadata_test.go
@@ -16,6 +16,7 @@ func TestMetadataIsInternalKey(t *testing.T) {
 		{"any.hostname.com/with/path", false},
 		{"any.kubernetes.io", true},
 		{"kubernetes.io", true},
+		{"notified.notifications.argoproj.io", true},
 	}
 	for i, tc := range testCases {
 		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {