diff --git a/R/rliger.R b/R/rliger.R
index 81570570..465bf032 100755
--- a/R/rliger.R
+++ b/R/rliger.R
@@ -4587,7 +4587,7 @@ getProportionMito <- function(object, use.norm = FALSE) {
     data.use <- object@norm.data
   }
   percent_mito <- unlist(lapply(unname(data.use), function(x) {
-    colSums(x[mito.genes, ]) / colSums(x)
+    colSums(x[rownames(x) %in% mito.genes, ]) / colSums(x)
   }), use.names = TRUE)
   
   return(percent_mito)
@@ -7161,4 +7161,4 @@ calcNormLoadings = function(object) {
   }
   
   return(results)
-}
\ No newline at end of file
+}