diff --git a/Dockerfile b/Dockerfile
index a5e36b1..1d4ab2e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -44,18 +44,21 @@ ENV KERL_DOC_TARGETS=""
 ENV KERL_INSTALL_HTMLDOCS="no"
 ENV KERL_INSTALL_MANPAGES="no"
 
-RUN git clone https://github.com/asdf-vm/asdf.git --branch v0.6.3 "$HOME"/.asdf && \
-    echo '. $HOME/.asdf/asdf.sh' >> "$HOME"/.bashrc && \
-        echo '. $HOME/.asdf/asdf.sh' >> "$HOME"/.profile
+# Install asdf and add it to PATH
+RUN git clone https://github.com/asdf-vm/asdf.git --branch v0.6.3 /root/.asdf && \
+    echo '. /root/.asdf/asdf.sh' >> /root/.bashrc && \
+    echo '. /root/.asdf/asdf.sh' >> /root/.profile
 
-ENV PATH="${PATH}:/root/.asdf/shims:/root/.asdf/bin"
+ENV PATH="/root/.asdf/shims:/root/.asdf/bin:${PATH}"
 
 RUN mkdir -p /opt/erlang/epp_proxy
 WORKDIR /opt/erlang/epp_proxy
 
 COPY .tool-versions ./
+
+# Install plugins and tools with explicit sourcing of asdf.sh
 RUN asdf plugin-add erlang
-RUN . $HOME/.asdf/asdf.sh && asdf install
+RUN source /root/.asdf/asdf.sh && asdf install
 RUN asdf global erlang $(grep erlang .tool-versions | cut -d' ' -f2)
 RUN asdf plugin-add ruby
 RUN asdf plugin-add rebar
diff --git a/README.md b/README.md
index 0a55f2a..c7832a0 100644
--- a/README.md
+++ b/README.md
@@ -105,20 +105,33 @@ Configuration for the application tries to emulate the mod_epp configuration as
 to make migration easier. The configuration is placed in `config/sys.config` file, it takes a format
 of Erlang property list.
 
+There are three example configuration files in `config/`:
+
+* `sys.config` – default configuration used for real deployments. Values such as `tls_port`,
+  `epp_session_url` and certificate paths are typically provided via environment variables (eg.
+  `${TLS_PORT}`, `${EPP_SESSION_URL}`), so the same file can be reused across environments.
+* `docker.config` – configuration tuned for running inside Docker. It uses hardcoded ports,
+  certificate paths under `/opt/ca/...` and EPP endpoints pointing to the `epp` container
+  (eg. `http://epp:3000/epp/…`).
+* `test.config` – local development/test configuration. It enables `dev_mode`, uses local ports
+  and points EPP endpoints to `http://localhost:9292/...`, with test CA material under
+  `test_ca/`.
+
 *Configuration variables*
 
-| Variable name        | Expected values                    | Apache equivalent     | Definition
------------------------|------------------------------------|-----------------------|--------------------------------------------
-| `dev_mode`           | `true`, `false`                    | None                  | Enables TCP access without TLS.
-| `tls_port`           | `700`                              | Listen                | At which port should we open a TLS socket. Default is 700.
-| `tcp_port`           | `70000`                            | Listen                | At which port should we open a TCP socket. Only in `dev_mode`.
-| `epp_session_url`    | `https://example.com/epp/session`  | EppSessionRoot        | HTTP address of the session endpoints including schema and port.
-| `epp_command_url`    | `https://example.com/epp/command`  | EppCommandRoot        | HTTP address of the command endpoints including schema and port.
-| `epp_error_url`      | `https://example.com/epp/error`    | EppErrorRoot          | HTTP address of the error endpoints including schema and port.
-| `cacertfile_path`    | `/opt/ca/ca.crt.pem`               | SSLCACertificateFile  | Where is the client root CA located. Can be inside apps/epp_proxy/priv or absolute path.
-| `certfile_path`      | `/opt/ca/server.crt.pem`           | SSLCertificateFile    | Where is the server certificate located. Can be inside apps/epp_proxy/priv or absolute path.
-| `keyfile_path`       | `/opt/ca/server.key.pem`           | SSLCertificateKeyFile | Where is the server key located. Can be inside apps/epp_proxy/priv or absolute path.
-| `crlfile_path`       | `/opt/ca/crl.pem`                  | SSLCARevocationFile   | Where is the CRL file located. Can be inside apps/epp_proxy/priv or absolute path. When not set, not CRL check is performed.
+| Variable name          | Expected values                    | Apache equivalent     | Definition
+-------------------------|------------------------------------|-----------------------|--------------------------------------------
+| `dev_mode`             | `true`, `false`                    | None                  | Enables TCP access without TLS.
+| `tls_port`             | `700`                              | Listen                | At which port should we open a TLS socket. Default is 700.
+| `tcp_port`             | `70000`                            | Listen                | At which port should we open a TCP socket. Only in `dev_mode`.
+| `epp_session_url`      | `https://example.com/epp/session`  | EppSessionRoot        | HTTP address of the session endpoints including schema and port.
+| `epp_command_url`      | `https://example.com/epp/command`  | EppCommandRoot        | HTTP address of the command endpoints including schema and port.
+| `epp_error_url`        | `https://example.com/epp/error`    | EppErrorRoot          | HTTP address of the error endpoints including schema and port.
+| `require_client_certs` | `true`, `false`                    | None                  | Allows client to connect to epp_proxy without client certificate using TLS.
+| `cacertfile_path`      | `/opt/ca/ca.crt.pem`               | SSLCACertificateFile  | Where is the client root CA located. Can be inside apps/epp_proxy/priv or absolute path.
+| `certfile_path`        | `/opt/ca/server.crt.pem`           | SSLCertificateFile    | Where is the server certificate located. Can be inside apps/epp_proxy/priv or absolute path.
+| `keyfile_path`         | `/opt/ca/server.key.pem`           | SSLCertificateKeyFile | Where is the server key located. Can be inside apps/epp_proxy/priv or absolute path.
+| `crlfile_path`         | `/opt/ca/crl.pem`                  | SSLCARevocationFile   | Where is the CRL file located. Can be inside apps/epp_proxy/priv or absolute path. When not set, not CRL check is performed.
 
 
 Migrating from mod_epp
diff --git a/apps/epp_proxy/src/epp_tls_acceptor.erl b/apps/epp_proxy/src/epp_tls_acceptor.erl
index a3c0080..c41a4e8 100644
--- a/apps/epp_proxy/src/epp_tls_acceptor.erl
+++ b/apps/epp_proxy/src/epp_tls_acceptor.erl
@@ -21,9 +21,10 @@ start_link(Port) ->
 			  []).
 
 init(Port) ->
+    RequireClientCerts = require_client_certs(),
     DefaultOptions = [binary, {packet, raw},
 		      {active, false}, {reuseaddr, true},
-		      {verify, verify_peer}, {depth, 1},
+		      {verify, verify_peer}, {fail_if_no_peer_cert, RequireClientCerts}, {depth, 1},
 		      {cacertfile, ca_cert_file()}, {certfile, cert_file()},
 		      {keyfile, key_file()}],
     Options = handle_crl_check_options(DefaultOptions),
@@ -82,6 +83,14 @@ key_file() ->
       {ok, KeyFile} -> epp_util:path_for_file(KeyFile)
     end.
 
+%% Whether client certificates are required.
+%% If not configured, default to true to preserve existing behavior.
+require_client_certs() ->
+    case application:get_env(epp_proxy, require_client_certs) of
+      undefined -> true;
+      {ok, Bool} -> Bool
+    end.
+
 crl_file() ->
     case application:get_env(epp_proxy, crlfile_path) of
       undefined -> undefined;
diff --git a/apps/epp_proxy/test/tls_client_optional_cert_SUITE.erl b/apps/epp_proxy/test/tls_client_optional_cert_SUITE.erl
new file mode 100644
index 0000000..bc49961
--- /dev/null
+++ b/apps/epp_proxy/test/tls_client_optional_cert_SUITE.erl
@@ -0,0 +1,36 @@
+-module(tls_client_optional_cert_SUITE).
+
+-include_lib("common_test/include/ct.hrl").
+
+-export([all/0, init_per_suite/1, end_per_suite/1,
+         connect_without_client_cert_test/1, connect_with_client_cert_test/1]).
+
+all() -> [connect_without_client_cert_test, connect_with_client_cert_test].
+
+init_per_suite(Config) ->
+    application:set_env(epp_proxy, require_client_certs, false),
+    application:ensure_all_started(epp_proxy),
+    application:ensure_all_started(hackney),
+    CWD = code:priv_dir(epp_proxy),
+    WithCert = [binary,
+                {certfile, filename:join(CWD, "test_ca/certs/client.crt.pem")},
+                {keyfile, filename:join(CWD, "test_ca/private/client.key.pem")},
+                {active, false}],
+    [{with_cert, WithCert} | Config].
+
+end_per_suite(Config) ->
+    application:unset_env(epp_proxy, require_client_certs),
+    application:stop(epp_proxy),
+    application:stop(hackney),
+    Config.
+
+connect_without_client_cert_test(_Config) ->
+    {ok, Socket} = ssl:connect("localhost", 1443, [binary, {active, false}], 2000),
+    {ok, _Data} = ssl:recv(Socket, 0, 1200),
+    ok.
+
+connect_with_client_cert_test(Config) ->
+    Options = proplists:get_value(with_cert, Config),
+    {ok, Socket} = ssl:connect("localhost", 1443, Options, 2000),
+    {ok, _Data} = ssl:recv(Socket, 0, 1200),
+    ok.
\ No newline at end of file
diff --git a/config/docker.config b/config/docker.config
index a8f8935..06efb97 100644
--- a/config/docker.config
+++ b/config/docker.config
@@ -8,10 +8,12 @@
                {epp_session_url, "http://epp:3000/epp/session/"},
                {epp_command_url, "http://epp:3000/epp/command/"},
                {epp_error_url, "http://epp:3000/epp/error/"},
+                %% Allows client to connect to epp_proxy without client certificate using TLS
+               {require_client_certs, true},
                {cacertfile_path, "/opt/ca/certs/ca.crt.pem"},
                {certfile_path, "/opt/ca/certs/apache.crt"},
-               {keyfile_path, "/opt/ca/private/apache.key"},
-               {crlfile_path, "/opt/ca/crl/crl.pem"}
+               {keyfile_path, "/opt/ca/private/apache.key"}
+               %% {crlfile_path, "/opt/ca/crl/crl.pem"}
 	       ]},
   {lager, [
     {handlers, [
diff --git a/config/sys.config b/config/sys.config
index 2ee9a24..ebc44a3 100644
--- a/config/sys.config
+++ b/config/sys.config
@@ -17,6 +17,8 @@
                {epp_session_url, "${EPP_SESSION_URL}"},
                {epp_command_url, "${EPP_COMMAND_URL}"},
                {epp_error_url, "${EPP_ERROR_URL}"},
+                %% Allows client to connect to epp_proxy without client certificate using TLS
+               {require_client_certs, true},
                %% Path to root CA that should check the client certificates.
                {cacertfile_path, "${CACERT_PATH}"},
                %% Path to server's certficate file.
diff --git a/config/test.config b/config/test.config
index 90cecb2..697715a 100644
--- a/config/test.config
+++ b/config/test.config
@@ -7,6 +7,8 @@
                {epp_session_url, "http://localhost:9292/session/"},
                {epp_command_url, "http://localhost:9292/command/"},
                {epp_error_url, "http://localhost:9292/error/"},
+                %% Allows client to connect to epp_proxy without client certificate using TLS
+               {require_client_certs, true},
                %% Path to root CA that should check the client certificates.
                {cacertfile_path, "test_ca/certs/ca.crt.pem"},
                {certfile_path, "test_ca/certs/apache.crt"},