diff --git a/scripts/native/cicd/hwlab-node-control-plane-refresh.mjs b/scripts/native/cicd/hwlab-node-control-plane-refresh.mjs
index b3d6b088..a068c0c7 100644
--- a/scripts/native/cicd/hwlab-node-control-plane-refresh.mjs
+++ b/scripts/native/cicd/hwlab-node-control-plane-refresh.mjs
@@ -102,10 +102,11 @@ function applyDeployOverlay() {
     runtimePath: overlay.runtimePath,
     imageTagMode: "full",
     sourceRepo: overlay.gitUrl,
-    externalPostgres: overlay.externalPostgres,
     observability: overlay.observability,
     envRecipe: { ...(lane.envRecipe || {}), downloadStack },
   };
+  if (overlay.externalPostgres === undefined || overlay.externalPostgres === null) delete doc.lanes[overlay.lane].externalPostgres;
+  else doc.lanes[overlay.lane].externalPostgres = overlay.externalPostgres;
   if (overlay.runtimeStore !== undefined) doc.lanes[overlay.lane].runtimeStore = overlay.runtimeStore;
   if (overlay.codeAgentRuntime !== undefined) doc.lanes[overlay.lane].codeAgentRuntime = overlay.codeAgentRuntime;
   if (overlay.deployYamlGitMirror !== undefined) doc.lanes[overlay.lane].gitMirror = overlay.deployYamlGitMirror;
diff --git a/scripts/src/hwlab-node/render.ts b/scripts/src/hwlab-node/render.ts
index 0018a31f..56216c29 100644
--- a/scripts/src/hwlab-node/render.ts
+++ b/scripts/src/hwlab-node/render.ts
@@ -1372,10 +1372,11 @@ export function renderNodeRuntimeControlPlaneOnNode(spec: HwlabRuntimeLaneSpec,
     "  runtimePath: overlay.runtimePath,",
     "  imageTagMode: 'full',",
     "  sourceRepo: overlay.gitUrl,",
-    "  externalPostgres: overlay.externalPostgres,",
     "  observability: overlay.observability,",
     "  envRecipe: { ...(lane.envRecipe || {}), downloadStack },",
     "};",
+    "if (overlay.externalPostgres === undefined || overlay.externalPostgres === null) delete doc.lanes[overlay.lane].externalPostgres;",
+    "else doc.lanes[overlay.lane].externalPostgres = overlay.externalPostgres;",
     "if (overlay.runtimeStore !== undefined) doc.lanes[overlay.lane].runtimeStore = overlay.runtimeStore;",
     "if (overlay.codeAgentRuntime !== undefined) doc.lanes[overlay.lane].codeAgentRuntime = overlay.codeAgentRuntime;",
     "if (overlay.deployYamlGitMirror !== undefined) doc.lanes[overlay.lane].gitMirror = overlay.deployYamlGitMirror;",
@@ -1519,10 +1520,11 @@ export function nodeRuntimePipelinePostprocessScript(): string[] {
     "  runtimePath: overlay.runtimePath,",
     "  imageTagMode: 'full',",
     "  sourceRepo: overlay.gitUrl,",
-    "  externalPostgres: overlay.externalPostgres,",
     "  observability: overlay.observability,",
     "  envRecipe: { ...envRecipe, downloadStack },",
     "};",
+    "if (overlay.externalPostgres === undefined || overlay.externalPostgres === null) delete doc.lanes[overlay.lane].externalPostgres;",
+    "else doc.lanes[overlay.lane].externalPostgres = overlay.externalPostgres;",
     "if (overlay.runtimeStore !== undefined) doc.lanes[overlay.lane].runtimeStore = overlay.runtimeStore;",
     "if (overlay.codeAgentRuntime !== undefined) doc.lanes[overlay.lane].codeAgentRuntime = overlay.codeAgentRuntime;",
     "if (overlay.deployYamlGitMirror !== undefined) doc.lanes[overlay.lane].gitMirror = overlay.deployYamlGitMirror;",