diff --git a/internal/graphqlTypes.go b/internal/graphqlTypes.go
index f089134..e41fd2c 100644
--- a/internal/graphqlTypes.go
+++ b/internal/graphqlTypes.go
@@ -55,7 +55,7 @@ func graphqlTypes() {
 				},
 			},
 			"size": &graphql.Field{
-				Type: graphql.Int,
+				Type: graphql.NewNonNull(graphql.Int),
 				Resolve: func(p graphql.ResolveParams) (interface{}, error) {
 					file, err := loadFile(p)
 					if err != nil {