diff --git a/src/fs/mount.rs b/src/fs/mount.rs
index d351476..9ced5f3 100644
--- a/src/fs/mount.rs
+++ b/src/fs/mount.rs
@@ -876,7 +876,7 @@ impl Display for Mount {
         write!(f, "mount")?;
 
         if !self.options.is_empty() {
-            write!(f, " -o {}", self.options)?;
+            write!(f, " {}", self.options)?;
         }
 
         write!(f, " {}", self.source)?;
@@ -1260,12 +1260,15 @@ mod tests {
 
     #[test]
     fn mount_display() {
-        let mnt = Mount::new(
+        let mut mnt = Mount::new(
             DeviceId::Label("awawa".into()),
             "/mnt",
             MountOptions::default(),
         );
 
         assert_eq!(mnt.to_string(), "mount LABEL=awawa /mnt");
+
+        mnt.options.push(MountOption::All);
+        assert_eq!(mnt.to_string(), "mount --all LABEL=awawa /mnt");
     }
 }