diff --git a/README.md b/README.md
index 56c9deb..10363b6 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Drivers **must** expose the following symbols:
 void driver_init(); // Initialization
 uint32_t driver_getkey(); // Calls to this function must return USB keys that this driver registers, until 0
 
-device_type_t driver_get_capacity(); // Returns device capacity (see below)
+device_capacity_t driver_get_capacity(void* handle); // Returns device capacity (see below)
 char* driver_get_name(void* handle); // Returns peripheral name
 char* driver_get_image(void* handle); // Returns peripheral image
 char* driver_get_manufacturer(void* handle); // Returns manufacturer name