diff --git a/.functions b/.functions
index bce0305db6..2e52df1a64 100644
--- a/.functions
+++ b/.functions
@@ -95,7 +95,10 @@ function phpserver() {
 
 # Compare original and gzipped file size
 function gz() {
-	local origsize=$(wc -c < "$1");
+	local origsize=$(
+		stat -Lf"%z" -- "$1" 2> /dev/null; # macOS `stat`
+		stat -Lc"%s" -- "$1" 2> /dev/null;  # GNU `stat`
+	);
 	local gzipsize=$(gzip -c "$1" | wc -c);
 	local ratio=$(echo "$gzipsize * 100 / $origsize" | bc -l);
 	printf "orig: %d bytes\n" "$origsize";