diff --git a/packages/mermaid-layout-elk/src/render.ts b/packages/mermaid-layout-elk/src/render.ts
index dbd23d381..2cb12e035 100644
--- a/packages/mermaid-layout-elk/src/render.ts
+++ b/packages/mermaid-layout-elk/src/render.ts
@@ -165,6 +165,7 @@ export const render = async (
         domId: { node: () => any; attr: (arg0: string, arg1: string) => void };
       }) {
         if (node) {
+          nodeDb[node.id] ??= {};
           nodeDb[node.id].offset = {
             posX: node.x + relX,
             posY: node.y + relY,