diff --git a/packages/pg/lib/utils.js b/packages/pg/lib/utils.js
index d63fe68f1..47823a306 100644
--- a/packages/pg/lib/utils.js
+++ b/packages/pg/lib/utils.js
@@ -78,7 +78,7 @@ function prepareObject(val, seen) {
 
     return prepareValue(val.toPostgres(prepareValue), seen)
   }
-  return JSON.stringify(val)
+  return JSON.stringify(val, (_, val) => typeof val === 'bigint' ? val.toString() : val)
 }
 
 function pad(number, digits) {