diff --git a/Ext4.h b/Ext4.h
index c5ab78a..54fbec3 100644
--- a/Ext4.h
+++ b/Ext4.h
@@ -23,7 +23,7 @@
 public:
     static int doMount(const char *fsPath, const char *mountPoint, bool ro, bool remount,
             bool executable);
-    static int format(const char *fsPath, const char *mountpoint);
+    static int format(const char *fsPath, unsigned int numSectors, const char *mountpoint);
 };
 
 #endif