diff --git a/R/splat-simulate.R b/R/splat-simulate.R
index 38bbf7d8760d371c6bea31b4826c84ae24083e3b..6684d2321b31a59efb058d1b88e9a49afa7ef906 100644
--- a/R/splat-simulate.R
+++ b/R/splat-simulate.R
@@ -356,8 +356,8 @@ splatSimBatchCellMeans <- function(sim, params) {
         batch.names <- unique(batches)
 
         batch.facs.gene <- rowData(sim)[, paste0("BatchFac", batch.names)]
-        batch.facs.cell <- as.matrix(batch.facs.gene[, factor(batches)])
-
+        batch.facs.cell <- as.matrix(batch.facs.gene[,
+                                                  as.numeric(factor(batches))])
     } else {
         nCells <- getParam(params, "nCells")
         nGenes <- getParam(params, "nGenes")