diff --git a/Ccs/ccs_function_lib.py b/Ccs/ccs_function_lib.py
index 67d8fed88c05184ba32fb3d404b677577c7db514..d5cacb4854e35d130da865fdad82d00860ad8414 100644
--- a/Ccs/ccs_function_lib.py
+++ b/Ccs/ccs_function_lib.py
@@ -2999,11 +2999,13 @@ def source_to_srec(data, outfile, memaddr, header=None, bytes_per_line=32, skip_
         raise ValueError("Maximum number of bytes per line is {}!".format(SREC_MAX_BYTES_PER_LINE))
 
     if isinstance(data, str):
-        data = open(data, 'rb').read()[skip_bytes:]
+        data = open(data, 'rb').read()
         
     if not isinstance(data, bytes):
         raise TypeError
 
+    data = data[skip_bytes:]
+
     if header is None:
         fname = outfile.split('/')[-1][-60:]
         header = 'S0{:02X}0000{:}'.format(len(fname.encode('ascii')) + 3, fname.encode('ascii').ljust(24).hex().upper())