diff --git a/ChangeLog.md b/ChangeLog.md
index f376ad9..6ac8d0c 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -15,6 +15,10 @@ repository history](https://github.com/ddclient/ddclient/commits/master).
     [5b104ad1](https://github.com/ddclient/ddclient/commit/5b104ad116c023c3760129cab6e141f04f72b406)
   * All log messages are now written to STDERR, not a mix of STDOUT and STDERR.
     [#676](https://github.com/ddclient/ddclient/pull/676)
+  * For `--protocol=freedns` and `--protocol=nfsn`, the core module
+    `Digest::SHA` is now required.  Previously, `Digest::SHA1` was used (if
+    available) as an alternative to `Digest::SHA`.
+    [#685](https://github.com/ddclient/ddclient/pull/685)
 
 ### New features
 
diff --git a/ddclient.in b/ddclient.in
index 51ce3f9..b758420 100755
--- a/ddclient.in
+++ b/ddclient.in
@@ -2600,21 +2600,14 @@ sub encode_base64 ($;$) {
 ## load_sha1_support
 ######################################################################
 sub load_sha1_support {
-    my $why         = shift;
-    my $sha1_loaded = eval { require Digest::SHA1 };
-    my $sha_loaded  = eval { require Digest::SHA };
-    unless ($sha1_loaded || $sha_loaded) {
-        fatal("%s", <<"EOM");
-Error loading the Perl module Digest::SHA1 or Digest::SHA needed for $why update.
-On Debian, the package libdigest-sha1-perl or libdigest-sha-perl must be installed.
+    my ($protocol) = @_;
+    eval { require Digest::SHA; } or fatal(<<"EOM");
+Error loading the Perl module Digest::SHA needed for $protocol update.
+On Debian, the package libdigest-sha-perl must be installed.
 EOM
-    }
-    if ($sha_loaded) {
-        Digest::SHA->import(qw/sha1_hex/);
-    } elsif ($sha1_loaded) {
-        Digest::SHA1->import(qw/sha1_hex/);
-    }
+    Digest::SHA->import(qw/sha1_hex/);
 }
+
 ######################################################################
 ## load_json_support
 ######################################################################