diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 73e3d3810e3f..477989d255be 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -20,7 +20,8 @@
 #define AUTOFS_IOC_COUNT     32
 
 #define AUTOFS_DEV_IOCTL_IOC_FIRST	(AUTOFS_DEV_IOCTL_VERSION)
-#define AUTOFS_DEV_IOCTL_IOC_COUNT	(AUTOFS_IOC_COUNT - 11)
+#define AUTOFS_DEV_IOCTL_IOC_COUNT \
+	(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index d47b35a669e1..13e75177f892 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -642,7 +642,7 @@ static int _autofs_dev_ioctl(unsigned int command,
 	cmd = _IOC_NR(command);
 
 	if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
-	    cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) {
+	    cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
 		return -ENOTTY;
 	}