diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index 4c405dc..0625c5f 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -11,15 +11,13 @@ on:
 jobs:
   CI:
     name: Build and test on Erlang/OTP ${{ matrix.otp-version }}
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
         otp-version: [23, 24]
-    env:
-      LATEST_OTP_RELEASE: 24
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: erlef/setup-beam@v1
         with:
           otp-version: ${{matrix.otp-version}}
diff --git a/Makefile b/Makefile
index 811fa49..ccfb30c 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ DEP_RANCH_VERSION = 2.1.0
 
 dep_ranch = ranch $(DEP_RANCH_VERSION)
 dep_eiconv = hex 1.0.0
-dep_gen_smtp = git https://github.com/gen-smtp/gen_smtp.git master
+dep_gen_smtp = git https://github.com/gen-smtp/gen_smtp.git 1.1.1
 
 DEPS = gen_smtp rabbit_common amqp_client rabbit eiconv
 
diff --git a/README.md b/README.md
index ad0d7db..d12ff1d 100644
--- a/README.md
+++ b/README.md
@@ -19,14 +19,14 @@ contributions are encouraged.
 
 ## Installation
 
-Due to the dependency on the `eiconv` library, which has a C source code component, this plugin must be compiled from source. If you are planning to use RabbitMQ version 3.9.10:
+Due to the dependency on the `eiconv` library, which has a C source code component, this plugin must be compiled from source. If you are planning to use RabbitMQ version 3.9.13:
 
 ```
 git clone https://github.com/gotthardp/rabbitmq-email.git
 cd rabbitmq-email
-make RABBITMQ_VERSION=v3.9.10
+make
 make tests # optional
-make dist
+make RABBITMQ_VERSION=v3.9.13 dist
 ```
 
 Copy the following directories to your RabbitMQ `plugins/` directory:
@@ -34,10 +34,10 @@ Copy the following directories to your RabbitMQ `plugins/` directory:
 ```
 plugins/eiconv-1.0.0
 plugins/gen_smtp-1.1.1
-plugins/rabbitmq_email-1.0.0
+plugins/rabbitmq_email-1.0.1
 ```
 
-Note that as of version 1.0.0 this plugin has been tested with RabbitMQ v3.9.x versions only.
+Note that as of version 1.0.1 this plugin has been tested with RabbitMQ v3.9.x versions only.
 
 ## Documentation
 
diff --git a/src/rabbit_email_sender.erl b/src/rabbit_email_sender.erl
index 0477960..2b2abdf 100644
--- a/src/rabbit_email_sender.erl
+++ b/src/rabbit_email_sender.erl
@@ -19,8 +19,14 @@ send_email(To, Domain, {Type, Subtype}, Headers, Payload) ->
         [{<<"From">>, construct_address(From, Domain)},
         {<<"To">>, ToAddr}],
 
-    Message = mimemail:encode({Type, Subtype,
-        lists:foldr(fun set_header/2, [], Headers2), [], Payload}),
+    Headers3 = lists:foldr(fun set_header/2, [], Headers2),
+    % Note FUTURE for gen_smtp 1.2.0:
+    % mimemail:encode argument:
+    % {Type, Subtype, Headers, ContentTypeParams, Parts}
+    % https://github.com/gen-smtp/gen_smtp/pull/190
+    % https://github.com/gen-smtp/gen_smtp/blob/1.1.1/src/mimemail.erl#L82-L89
+    % https://github.com/gen-smtp/gen_smtp/blob/c6f25a758d60da9788bf5ddf73e985dacb28f74b/src/mimemail.erl#L98-L108
+    Message = mimemail:encode({Type, Subtype, Headers3, [], Payload}),
 
     % client_sender must be a valid user, whereas From doesn't have to
     {ok, Sender} = application:get_env(rabbitmq_email, client_sender),
diff --git a/src/rabbitmq_email.app.src b/src/rabbitmq_email.app.src
index 2b7edc3..bac401b 100644
--- a/src/rabbitmq_email.app.src
+++ b/src/rabbitmq_email.app.src
@@ -9,7 +9,7 @@
 
 {application, rabbitmq_email,
     [{description, " E-mail gateway for AMQP 0-9-1"},
-    {vsn, "1.0.0"},
+    {vsn, "1.0.1"},
     {modules, []},
     {registered, []},
     {mod, {rabbitmq_email_app, []}},