diff --git a/src/error/GraphQLError.js b/src/error/GraphQLError.js
index 7552bb473d1..d3068adacbf 100644
--- a/src/error/GraphQLError.js
+++ b/src/error/GraphQLError.js
@@ -56,7 +56,7 @@ export class GraphQLError extends Error {
   /**
    * The original error thrown from a field resolver during execution.
    */
-  +originalError: Error | void;
+  +originalError: Error | void | null;
 
   /**
    * Extension fields to add to the formatted error.