diff --git a/intelhex/__init__.py b/intelhex/__init__.py
index 8af27c3..28ff48d 100644
--- a/intelhex/__init__.py
+++ b/intelhex/__init__.py
@@ -532,7 +532,7 @@ class IntelHex(object):
         """Return count of bytes with real values."""
         return len(dict_keys(self._buf))
 
-    def write_hex_file(self, f, write_start_addr=True):
+    def write_hex_file(self, f, write_start_addr=True, data_rec_len=16):
         """Write data to file f in HEX format.
 
         @param  f                   filename or file-like object for writing
@@ -639,7 +639,7 @@ class IntelHex(object):
                     # produce one record
                     low_addr = cur_addr & 0x0FFFF
                     # chain_len off by 1
-                    chain_len = min(15, 65535-low_addr, maxaddr-cur_addr)
+                    chain_len = min(data_rec_len-1, 65535-low_addr, maxaddr-cur_addr)
 
                     # search continuous chain
                     stop_addr = cur_addr + chain_len