diff --git a/libretro.h b/libretro.h
index f765a66047..7fd75067c8 100755
--- a/libretro.h
+++ b/libretro.h
@@ -435,7 +435,7 @@ struct retro_keyboard_callback
     retro_keyboard_event_t callback;
 };
 
-// Callback for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
+// Callbacks for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
 // Should be set for implementations which can swap out multiple disk images in runtime.
 // If the implementation can do this automatically, it should strive to do so.
 // However, there are cases where the user must manually do so.
@@ -443,9 +443,10 @@ struct retro_keyboard_callback
 // Overview: To swap a disk image, eject the disk image with set_eject_state(true).
 // Set the disk index with set_image_index(index). Insert the disk again with set_eject_state(false).
 
-// If ejected is true, "ejects" the virtual disk tray. When ejected, the disk image index can be set.
+// If ejected is true, "ejects" the virtual disk tray.
+// When ejected, the disk image index can be set.
 typedef bool (*retro_set_eject_state_t)(bool ejected);
-// Gets current eject state. The initial state is not ejected.
+// Gets current eject state. The initial state is 'not ejected'.
 typedef bool (*retro_get_eject_state_t)(void);
 // Gets current disk index. First disk is index 0.
 // If return value is >= get_num_images(), no disk is currently inserted.
@@ -455,6 +456,16 @@ typedef unsigned (*retro_get_image_index_t)(void);
 typedef bool (*retro_set_image_index_t)(unsigned index);
 // Gets total number of images which are available to use.
 typedef unsigned (*retro_get_num_images_t)(void);
+//
+// Replaces the disk image associated with index.
+// Arguments to pass in info have same requirements as retro_load_game().
+// Virtual disk tray must be ejected when calling this.
+struct retro_game_info;
+typedef bool (*retro_replace_image_index_t)(unsigned index, const struct retro_game_info *info);
+// Adds a new valid index (get_num_images()) to the internal disk list.
+// This will increment subsequent return values from get_num_images() by 1.
+// This image index cannot be used until a disk image has been set with replace_image_index.
+typedef bool (*retro_add_image_index_t)(void);
 
 struct retro_disk_control_callback
 {
@@ -464,6 +475,9 @@ struct retro_disk_control_callback
    retro_get_image_index_t get_image_index;
    retro_set_image_index_t set_image_index;
    retro_get_num_images_t  get_num_images;
+
+   retro_replace_image_index_t replace_image_index;
+   retro_add_image_index_t add_image_index;
 };
 
 enum retro_pixel_format