diff --git a/source/decryptor/nand.c b/source/decryptor/nand.c
index c942923..34b365f 100644
--- a/source/decryptor/nand.c
+++ b/source/decryptor/nand.c
@@ -81,6 +81,8 @@ u32 CheckEmuNand(void)
 
     // check the MBR for presence of a hidden partition
     u32 hidden_sectors = NumHiddenSectors();
+    if (hidden_sectors > 4 * multi_sectors)
+        hidden_sectors = 4 * multi_sectors;
     
     for (u32 offset_sector = 0; offset_sector + nand_size_sectors_min <= hidden_sectors; offset_sector += multi_sectors) {
         // check for RedNAND type EmuNAND
diff --git a/source/decryptor/nand.h b/source/decryptor/nand.h
index 79b0994..fe1b113 100644
--- a/source/decryptor/nand.h
+++ b/source/decryptor/nand.h
@@ -13,9 +13,6 @@
 #define P_FIRM1     (1<<4)
 #define P_CTRNAND   (1<<5)
 
-// force slot 0x04 for CTRNAND padgen
-#define PG_FORCESLOT4 (1<<0)
-
 // options for NAND backup & restore
 #define NB_MINSIZE  (1<<10)
 #define NR_NOCHECKS (1<<11)
@@ -53,7 +50,6 @@ u32 InputFileNameSelector(char* filename, const char* basename, char* extension,
 
 u32 DecryptNandToMem(u8* buffer, u32 offset, u32 size, PartitionInfo* partition);
 u32 DecryptNandToFile(const char* filename, u32 offset, u32 size, PartitionInfo* partition);
-u32 DecryptNandToHash(u8* hash, u32 offset, u32 size, PartitionInfo* partition);
 u32 EncryptMemToNand(u8* buffer, u32 offset, u32 size, PartitionInfo* partition);
 u32 EncryptFileToNand(const char* filename, u32 offset, u32 size, PartitionInfo* partition);
 
diff --git a/source/fs.c b/source/fs.c
index 3c5f58c..3c8d34e 100644
--- a/source/fs.c
+++ b/source/fs.c
@@ -394,5 +394,5 @@ uint64_t TotalStorageSpace()
 
 uint32_t NumHiddenSectors()
 {
-    return (uint32_t) fs.volbase - 1;
+    return (fs.volbase > 0) ? (uint32_t) fs.volbase - 1 : 0;
 }