diff --git a/R/output.R b/R/output.R
index ed50670..f142bd7 100644
--- a/R/output.R
+++ b/R/output.R
@@ -108,11 +108,11 @@ outputParametersToFile <- function(hmmResults, file){
 		write.table(paste0("Coverage:\t", coverage), file = fc, col.names = FALSE, 
 								row.names = FALSE, quote = FALSE, sep = "\t")
 	
-    if (!is.null(x$chrYCov)){
+    if (!is.null(x$chrYCov) || !is.na(x$chrYCov)){
       write.table(paste0("ChrY coverage fraction:\t", signif(x$chrYCov[s], digits = 4)), file = fc, col.names = FALSE, 
                   row.names = FALSE, quote = FALSE, sep = "\t")
     }
-    if (!is.null(x$chrXMedian)){
+    if (!is.null(x$chrXMedian) || !is.na(x$chrXMedian)){
       write.table(paste0("ChrX median log ratio:\t", signif(x$chrXMedian[s], digits = 4)), file = fc, col.names = FALSE, 
                   row.names = FALSE, quote = FALSE, sep = "\t")
     }
diff --git a/R/utils.R b/R/utils.R
index 318e589..bf64931 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -251,7 +251,7 @@ getGender <- function(rawReads, normReads, gc, map, fracReadsInChrYForMale = 0.0
 	}else{
 		gender <- "unknown" # chrX is not provided
 		chrYCov <- NA
-		chrXMedian <- NULL
+		chrXMedian <- NA
 	}
 	return(list(gender=gender, chrYCovRatio=chrYCov, chrXMedian=chrXMedian))
 }