diff --git a/NAMESPACE b/NAMESPACE
index ffa1c6b..6c5c4e0 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -145,7 +145,6 @@ export(sample_cells)
 export(sort_features)
 export(top_deg)
 import(Biobase, except = combine)
-import(Matrix)
 import(SeuratObject)
 import(SingleCellExperiment)
 import(SummarizedExperiment, except = Assays)
@@ -155,6 +154,8 @@ import(tibble)
 import(tidyr)
 importFrom(ComplexHeatmap,Heatmap)
 importFrom(ComplexHeatmap,columnAnnotation)
+importFrom(GenomeInfoDb,standardChromosomes)
+importFrom(Matrix,t)
 importFrom(Seurat,FindClusters)
 importFrom(Seurat,FindNeighbors)
 importFrom(Seurat,FindVariableFeatures)
diff --git a/R/scmisc-package.R b/R/scmisc-package.R
index 289722a..d0e432e 100644
--- a/R/scmisc-package.R
+++ b/R/scmisc-package.R
@@ -4,7 +4,9 @@
 # The following block is used by usethis to automatically manage
 # roxygen namespace tags. Modify with care!
 ## usethis namespace: start
-#' @import tibble dplyr tidyr ggplot2 SingleCellExperiment SeuratObject Matrix
+#' @import tibble dplyr tidyr ggplot2 SingleCellExperiment SeuratObject
+#' @importFrom Matrix t
+#' @importFrom GenomeInfoDb standardChromosomes
 #' @importFrom readr read_tsv
 #' @importFrom forcats fct_inseq
 #' @importFrom patchwork wrap_plots plot_layout