diff --git a/R/info.R b/R/info.R
index 89c62d5b..278a0eeb 100644
--- a/R/info.R
+++ b/R/info.R
@@ -165,7 +165,7 @@ neuprint_ROI_hierarchy <- function(root=NULL, rval=c("edgelist","graph"),
       as.character(x)
     else
       x
-  }, simplify = FALSE))
+  }, simplify = FALSE), stringsAsFactors=FALSE)
   g=igraph::graph_from_data_frame(el, directed = TRUE)
   if(!is.null(root)) {
     if(isFALSE(root%in%names(igraph::V(g))))
diff --git a/tests/testthat/testdata/hemibrain_neuprint_ROI_hierarchy.rds b/tests/testthat/testdata/hemibrain_neuprint_ROI_hierarchy.rds
index eceb0cc2..f9ffa0a9 100644
Binary files a/tests/testthat/testdata/hemibrain_neuprint_ROI_hierarchy.rds and b/tests/testthat/testdata/hemibrain_neuprint_ROI_hierarchy.rds differ