diff --git a/bootstrap/apps/argocd.yaml b/bootstrap/apps/argocd.yaml
index 895c19d..19e27d1 100644
--- a/bootstrap/apps/argocd.yaml
+++ b/bootstrap/apps/argocd.yaml
@@ -20,3 +20,12 @@ spec:
   destination:
     server: https://kubernetes.default.svc
     namespace: argocd
+  # ArgoCD was originally `helm install`ed by hand before ArgoCD existed to
+  # manage it (see README Phase 3), so client-side 3-way merge apply can't
+  # see/prune fields from that pre-existing object — left a stale `args` on
+  # argocd-repo-server's copyutil init container after a later chart bump,
+  # crashlooping it (same bug class as envoy-gateway, see 020b248).
+  # ServerSideApply properly tracks field ownership and prunes it.
+  syncPolicy:
+    syncOptions:
+      - ServerSideApply=true