diff --git a/lib/filesystem.js b/lib/filesystem.js
index b0da8c7..0677f2c 100644
--- a/lib/filesystem.js
+++ b/lib/filesystem.js
@@ -150,7 +150,7 @@ function fsSize(drive, callback) {
         }
         if (_linux) {
           try {
-            cmd = 'export LC_ALL=C; df -lkPTx squashfs; unset LC_ALL';
+            cmd = 'export LC_ALL=C; df -kPTx squashfs; unset LC_ALL';
             execSync('cat /proc/mounts 2>/dev/null', util.execOptsLinux)
               .toString()
               .split('\n')
@@ -169,7 +169,7 @@ function fsSize(drive, callback) {
         }
         if (_freebsd || _openbsd || _netbsd) {
           try {
-            cmd = 'df -lkPT';
+            cmd = 'df -kPT';
             execSync('mount')
               .toString()
               .split('\n')