diff --git a/libntfs-3g/ioctl.c b/libntfs-3g/ioctl.c
index 66cedaf9..b059a53f 100644
--- a/libntfs-3g/ioctl.c
+++ b/libntfs-3g/ioctl.c
@@ -389,7 +389,8 @@ static int fstrim(ntfs_volume *vol, void *data, u64 *trimmed)
 
 #endif /* FITRIM && BLKDISCARD */
 
-int ntfs_ioctl(ntfs_inode *ni, int cmd, void *arg __attribute__((unused)),
+int ntfs_ioctl(ntfs_inode *ni, unsigned long cmd,
+			void *arg __attribute__((unused)),
 			unsigned int flags __attribute__((unused)), void *data)
 {
 	int ret = 0;