diff --git a/scRNA-seq/04-dimension_reduction_scRNA.Rmd b/scRNA-seq/04-dimension_reduction_scRNA.Rmd
index 13b00696..19089b04 100644
--- a/scRNA-seq/04-dimension_reduction_scRNA.Rmd
+++ b/scRNA-seq/04-dimension_reduction_scRNA.Rmd
@@ -253,7 +253,7 @@ filtered_sce <- filtered_sce[, filtered_sce$sum >= 500]
 
 qclust <- scran::quickCluster(filtered_sce)
 
-filtered_sce <- scran::computeSumFactors(filtered_sce, clusters = qclust, positive = FALSE)
+filtered_sce <- scran::computeSumFactors(filtered_sce, clusters = qclust)
 ```
 
 Looks good! Now we'll do the normalization.