diff --git a/rebar.config b/rebar.config
index 615bd6a..cd58c5e 100644
--- a/rebar.config
+++ b/rebar.config
@@ -5,7 +5,7 @@
 
 {deps, [
         {jsx, ".*", {git, "git://github.com/talentdeficit/jsx.git", {tag, "v2.7.0"}}},
-        {ibrowse, "", {git, "git://github.com/cmullaparthi/ibrowse.git", {tag, "v4.0.2"}}}
+        {ibrowse, "", {git, "git://github.com/cmullaparthi/ibrowse.git", {tag, "v4.1.2"}}}
        ]}.
 
 {require_otp_vsn, "R16|17|18"}.
diff --git a/src/ddb.app.src b/src/ddb.app.src
index 2071fed..bc7d0b6 100644
--- a/src/ddb.app.src
+++ b/src/ddb.app.src
@@ -4,7 +4,7 @@
 {application, ddb,
  [
   {description, "AWS DynamoDB client"},
-  {vsn, "0.1.2"},
+  {vsn, "0.1.3"},
   {registered, [ddb_sup]},
   {applications, [
                   kernel,
diff --git a/src/ddb.erl b/src/ddb.erl
index 4b5c16f..da4a318 100644
--- a/src/ddb.erl
+++ b/src/ddb.erl
@@ -511,8 +511,8 @@ authorization(AccessKeyId, SecretAccessKey, Headers, Body) ->
 
 signature(SecretAccessKey, Headers, Body) ->
     StringToSign = lists:flatten(["POST", $\n, "/", $\n, $\n, canonical(Headers), $\n, Body]),
-    BytesToSign = crypto:sha(StringToSign),
-    base64:encode_to_string(binary_to_list(crypto:sha_mac(SecretAccessKey, BytesToSign))).
+    BytesToSign = crypto:hash(sha, StringToSign),
+    base64:encode_to_string(binary_to_list(crypto:hmac(sha, SecretAccessKey, BytesToSign))).
 
 -spec canonical(proplists:proplist()) -> [_].
 
diff --git a/src/ddb_iam.erl b/src/ddb_iam.erl
index c95df77..9f55f25 100644
--- a/src/ddb_iam.erl
+++ b/src/ddb_iam.erl
@@ -93,7 +93,7 @@ request(Action, Endpoint, Duration) ->
     CanonicalString = mochiweb_util:urlencode(lists:sort(Args)),
     #url{host=Host, path=Path} = ibrowse_lib:parse_url(Endpoint),
     S = ["POST", $\n, Host, $\n, Path, $\n, CanonicalString],
-    Signature = base64:encode_to_string(crypto:sha_mac(SecretAccessKey, S)),
+    Signature = base64:encode_to_string(crypto:hmac(sha, SecretAccessKey, S)),
     Args1 = [{"Signature", Signature}|Args],
     Body = iolist_to_binary(mochiweb_util:urlencode(lists:sort(Args1))), 
     F = fun() -> ibrowse:send_req(Endpoint, [{'Content-type', ?MIME_TYPE}], 'post', Body, []) end,
diff --git a/src/ddb_util.erl b/src/ddb_util.erl
index 2aff8ce..05f1980 100644
--- a/src/ddb_util.erl
+++ b/src/ddb_util.erl
@@ -72,7 +72,7 @@ first([{value, _} = R | _]) -> R.
 %% @end
 -spec epoch() -> integer().
 epoch() ->
-    {MS, S, _US} = now(),
+    {MS, S, _US} = os:timestamp(),
     MS * 1000000 + S.
 
 %% @doc Generate the number of seconds since Epoch to `DateTime'