diff --git a/fips/fips_check_sha1 b/fips/fips_check_sha1
index d24f4e214..51b40ec6d 100755
--- a/fips/fips_check_sha1
+++ b/fips/fips_check_sha1
@@ -5,4 +5,4 @@ shift
 
 egrep 'define OPENSSL_FIPS' $TOP/include/openssl/opensslconf.h > /dev/null || exit 0
 
-$TOP/fips/sha1/fips_standalone_sha1 $@ | diff -u $FP - || { echo; echo "*** Your source code does not match the FIPS certified source ***"; echo; exit 1; }
+$TOP/fips/sha1/fips_standalone_sha1 $@ | diff $FP - || { echo; echo "*** Your source code does not match the FIPS certified source ***"; echo; exit 1; }