diff --git a/libfsxfs/libfsxfs_volume.c b/libfsxfs/libfsxfs_volume.c
index 4a4e153..a3d39de 100644
--- a/libfsxfs/libfsxfs_volume.c
+++ b/libfsxfs/libfsxfs_volume.c
@@ -2349,6 +2349,8 @@ static int libfsxfs_allocation_group_traverse_alloc_tree(
     uint16_t num_records   = 0;
     uint16_t record_index  = 0;
     uint32_t magic_number  = 0;
+    const size_t rec_size  = 8;
+    const size_t ptr_size  = 4;
 
     if( file_io_handle == NULL )
     {
@@ -2417,12 +2419,10 @@ static int libfsxfs_allocation_group_traverse_alloc_tree(
     if( magic_number == LIBFSXFS_BB_V5_MAGIC_NUMBER )
     {
         header_size = 56;
-        max_records = 505;
     }
     else if( magic_number == LIBFSXFS_BB_V4_MAGIC_NUMBER )
     {
-        header_size = 18;
-        max_records = 509;
+        header_size = 16;
     }
     else
     {
@@ -2444,9 +2444,8 @@ static int libfsxfs_allocation_group_traverse_alloc_tree(
 
     if( tree_level > 1 )
     {
-        size_t key_size            = 4;
-        size_t ptr_size            = 4;
-        size_t pointer_array_start = header_size + ( max_records * key_size );
+        max_records = (block_size - header_size) / (rec_size + ptr_size);
+        size_t pointer_array_start = header_size + ( max_records * rec_size );
 
         for( record_index = 0; record_index < num_records; record_index++ )
         {
@@ -2479,10 +2478,8 @@ static int libfsxfs_allocation_group_traverse_alloc_tree(
             }
         }
     }
-    else if( tree_level == 1 )
+    else
     {
-        size_t rec_size = 8;
-
         for( record_index = 0; record_index < num_records; record_index++ )
         {
             uint32_t start_block = 0;