diff --git a/tools/icu/icutrim.py b/tools/icu/icutrim.py
index 29a05aa4624f..7f0fb3752e40 100755
--- a/tools/icu/icutrim.py
+++ b/tools/icu/icutrim.py
@@ -154,8 +154,8 @@ def runcmd(tool, cmd, doContinue=False):
     print "%s: %s" % (options.filterfile, config["comment"])
 
 ## STEP 1 - copy the data file, swapping endianness
-endian_letter = "l"
-
+## The first letter of endian_letter will be 'b' or 'l' for big or little
+endian_letter = options.endian[0]
 
 runcmd("icupkg", "-t%s %s %s""" % (endian_letter, options.datfile, outfile))