diff --git a/export.py b/export.py
index 8d43156..ffcb506 100644
--- a/export.py
+++ b/export.py
@@ -124,13 +124,10 @@ def version1_export(model, filepath):
 
     out_file = open(filepath, 'wb')
     # first write out the header. the header will be 256 bytes
-    nbytes = 0
     # 1) write magic, which will be uint32 of "ak42" in ASCII
     out_file.write(struct.pack('I', 0x616b3432))
-    nbytes += 4
     # 2) write version, which will be int
     out_file.write(struct.pack('i', version))
-    nbytes += 4
     # 3) write the params, which will be 7 ints
     p = model.params
     hidden_dim = model.layers[0].feed_forward.w1.weight.shape[0]
@@ -138,12 +135,10 @@ def version1_export(model, filepath):
     header = struct.pack('iiiiiii', p.dim, hidden_dim, p.n_layers, p.n_heads,
                                     n_kv_heads, p.vocab_size, p.max_seq_len)
     out_file.write(header)
-    nbytes += 7*4
     # 4) write some other flags
     shared_classifier = 1 # we do share a classifier, write flag as a byte
     out_file.write(struct.pack('B', shared_classifier))
-    nbytes += 1
-    pad = 256 - nbytes # pad the rest with zeros
+    pad = 256 - out_file.tell() # pad rest with zeros; tell returns current pos
     assert pad >= 0
     out_file.write(b'\0' * pad)
 
@@ -198,13 +193,10 @@ def version2_export(model, filepath, group_size=64):
     # write
     out_file = open(filepath, 'wb')
     # first write out the header. the header will be 256 bytes
-    nbytes = 0
     # 1) write magic, which will be uint32 of "ak42" in ASCII
     out_file.write(struct.pack('I', 0x616b3432))
-    nbytes += 4
     # 2) write version, which will be int
     out_file.write(struct.pack('i', version))
-    nbytes += 4
     # 3) write the params, which will be 7 ints
     p = model.params
     hidden_dim = model.layers[0].feed_forward.w1.weight.shape[0]
@@ -212,14 +204,11 @@ def version2_export(model, filepath, group_size=64):
     header = struct.pack('iiiiiii', p.dim, hidden_dim, p.n_layers, p.n_heads,
                                     n_kv_heads, p.vocab_size, p.max_seq_len)
     out_file.write(header)
-    nbytes += 7*4
     # 4) write some other flags
     shared_classifier = 1 # we do share a classifier, write flag as a byte
     out_file.write(struct.pack('B', shared_classifier))
-    nbytes += 1
     out_file.write(struct.pack('i', group_size)) # group size used for quantization
-    nbytes += 4
-    pad = 256 - nbytes # pad the rest with zeros
+    pad = 256 - out_file.tell() # pad rest with zeros; tell returns current pos
     assert pad >= 0
     out_file.write(b'\0' * pad)
     # now that the header is done, let's write out the model