diff --git a/packages/core/src/models/modelsConfig.ts b/packages/core/src/models/modelsConfig.ts
index 1c1569f42..d34cc08c6 100644
--- a/packages/core/src/models/modelsConfig.ts
+++ b/packages/core/src/models/modelsConfig.ts
@@ -905,6 +905,8 @@ export class ModelsConfig {
           : undefined;
         const savedApiKeySource = isUnchanged
           ? this.generationConfigSources['apiKey']
+            ? { ...this.generationConfigSources['apiKey'] }
+            : undefined
           : undefined;
 
         this.applyResolvedModelDefaults(resolved);