diff --git a/src/meta/fsb5_fev.c b/src/meta/fsb5_fev.c
index 8ba87452..105c4c8b 100644
--- a/src/meta/fsb5_fev.c
+++ b/src/meta/fsb5_fev.c
@@ -3,7 +3,7 @@
 #include "../util/chunks.h"
 
 
-static int get_subsongs(STREAMFILE* sf, off_t fsb5_offset, size_t fsb5_size);
+static int get_subsongs(STREAMFILE* sf, uint32_t fsb5_offset, uint32_t fsb5_size);
 
 /* FEV+FSB5 container [Just Cause 3 (PC), Shantae: Half-Genie Hero (Switch)] */
 VGMSTREAM* init_vgmstream_fsb5_fev_bank(STREAMFILE* sf) {
@@ -88,7 +88,7 @@ VGMSTREAM* init_vgmstream_fsb5_fev_bank(STREAMFILE* sf) {
 
         /* 0x00: unknown (chunk version? ex LE: 0x00080003, 0x00080005) */
         banks = (bank_size - 0x04) / entry_size;
-        
+
         /* multiple banks is possible but rare [Hades (Switch), Guacamelee 2 (Switch)],
          * must map bank (global) subsong to FSB (internal) subsong */
 
@@ -99,11 +99,11 @@ VGMSTREAM* init_vgmstream_fsb5_fev_bank(STREAMFILE* sf) {
         total_subsongs = 0;
         for (i = 0; i < banks; i++) {
             //TODO: fsb5_size fails for v0x28< + encrypted, but only used with multibanks = unlikely
-            off_t fsb5_offset  = read_u32le(bank_offset + 0x04 + entry_size*i + 0x00,sf);
-            size_t fsb5_size   = read_u32le(bank_offset+0x08 + entry_size*i,sf);
+            uint32_t fsb5_offset  = read_u32le(bank_offset + 0x04 + entry_size*i + 0x00,sf);
+            uint32_t fsb5_size   = read_u32le(bank_offset + 0x08 + entry_size*i,sf);
             int fsb5_subsongs = get_subsongs(sf, fsb5_offset, fsb5_size);
             if (!fsb5_subsongs) {
-                vgm_logi("FSB: couldn't load bank (encrypted?)\n");
+                vgm_logi("FSB: couldn't load bank %i at %x (encrypted?)\n", i, fsb5_offset);
                 goto fail;
             }
 
@@ -159,14 +159,13 @@ fail:
     return NULL;
 }
 
-static int get_subsongs(STREAMFILE* sf, off_t fsb5_offset, size_t fsb5_size) {
+static int get_subsongs(STREAMFILE* sf, uint32_t fsb5_offset, uint32_t fsb5_size) {
     VGMSTREAM* vgmstream = NULL;
     STREAMFILE* temp_sf = NULL;
     int subsongs = 0;
 
-
     /* standard */
-    if (read_u32be(fsb5_offset, sf) == 0x46534235) { /* FSB5 */
+    if (is_id32be(fsb5_offset, sf, "FSB5")) {
         return read_s32le(fsb5_offset + 0x08,sf);
     }
 
@@ -174,6 +173,7 @@ static int get_subsongs(STREAMFILE* sf, off_t fsb5_offset, size_t fsb5_size) {
     temp_sf = setup_subfile_streamfile(sf, fsb5_offset, fsb5_size, "fsb");
     if (!temp_sf) goto end;
 
+    temp_sf->stream_index = 0;
     vgmstream = init_vgmstream_fsb_encrypted(temp_sf);
     if (!vgmstream) goto end;
 
diff --git a/src/meta/fsb_encrypted_streamfile.h b/src/meta/fsb_encrypted_streamfile.h
index 1492366a..fdde3f2f 100644
--- a/src/meta/fsb_encrypted_streamfile.h
+++ b/src/meta/fsb_encrypted_streamfile.h
@@ -1,7 +1,7 @@
 #ifndef _FSB_ENCRYPTED_STREAMFILE_H_
 #define _FSB_ENCRYPTED_STREAMFILE_H_
 
-#define FSB_KEY_MAX 0x10000 //0x168
+#define FSB_KEY_MAX 0x80 /* known max ~0x33 */
 
 
 typedef struct {
@@ -57,7 +57,7 @@ static STREAMFILE* setup_fsb_streamfile(STREAMFILE* sf, const uint8_t* key, size
     size_t io_data_size = sizeof(fsb_decryption_data);
 
     /* setup decryption with key (external) */
-    if (!key_size || key_size > FSB_KEY_MAX)
+    if (!key_size || key_size >= FSB_KEY_MAX)
         return NULL;
 
     memcpy(io_data.key, key, key_size);