diff --git a/ecs/Dockerfile b/ecs/Dockerfile
index 140a936..761df91 100644
--- a/ecs/Dockerfile
+++ b/ecs/Dockerfile
@@ -4,6 +4,7 @@ RUN go install -v \
     && mv bin/ejabberd bin/ejabberdapi
 
 FROM ejabberd/mix as builder
+ARG BUILD_DIR='/ejabberd'
 ARG VERSION
 ENV VERSION=${VERSION:-latest} \
     MIX_ENV=prod
@@ -12,7 +13,23 @@ LABEL maintainer="ProcessOne <contact@process-one.net>" \
 
 # Get ejabberd sources, dependencies, configuration
 RUN git clone https://github.com/processone/ejabberd.git
-WORKDIR /ejabberd
+
+# include mod_ecaptcha from ejabberd-contrib
+WORKDIR $BUILD_DIR/.ejabberd-modules/sources/ejabberd-contrib
+RUN git clone https://github.com/processone/ejabberd-contrib --depth 1 . \
+    && cp mod_ecaptcha/src/mod_ecaptcha.erl $BUILD_DIR/src \
+    && sed -i '/^{deps,/a \ \
+        \n        {ecaptcha, ".*", {git, "https://github.com/seriyps/ecaptcha", {branch, "master"}}},' \
+            $BUILD_DIR/rebar.config \
+    && sed -i '/^     {:xmpp, ">= .*"},/a \ \
+        \n     {:ecaptcha, github: "seriyps/ecaptcha"},' \
+            $BUILD_DIR/mix.exs \
+    && sed -i '/^     included_applications:/a \ \
+        \n                             :ecaptcha,' \
+            $BUILD_DIR/mix.exs \
+    && rm -rf mod_ecaptcha
+
+WORKDIR $BUILD_DIR
 COPY vars.config .
 RUN echo '{vsn, "'${VERSION}'.0"}.' >>vars.config
 COPY config.exs config/
@@ -25,9 +42,8 @@ RUN git checkout ${VERSION/latest/HEAD} \
 RUN MIX_ENV=prod mix release
 
 # Prepare runtime environment
-RUN mkdir runtime \
-    && tar -C runtime -zxf _build/prod/ejabberd-*.tar.gz \
-    && cd runtime \
+WORKDIR $BUILD_DIR/runtime
+RUN tar -zxf $BUILD_DIR/_build/prod/ejabberd-*.tar.gz \
     && cp releases/*/start.boot bin \
     && cp releases/*/start_clean.boot bin \
     && echo 'beam_lib:strip_files(filelib:wildcard("lib/*/ebin/*beam")), init:stop().' | erl >/dev/null \
@@ -38,8 +54,8 @@ RUN mkdir runtime \
     && mkdir lib/ejabberd-$EJABBERD_VERSION/priv/bin \
     && cp /usr/lib/elixir/bin/* bin/ \
     && sed -i 's|ERL_EXEC="erl"|ERL_EXEC="/home/ejabberd/bin/erl"|' bin/elixir \
-    && cp /ejabberd/tools/captcha*sh lib/ejabberd-$EJABBERD_VERSION/priv/bin \
-    && cp -r /ejabberd/sql lib/ejabberd-*/priv
+    && cp $BUILD_DIR/tools/captcha*sh lib/ejabberd-$EJABBERD_VERSION/priv/bin \
+    && cp -r $BUILD_DIR/sql lib/ejabberd-*/priv
 
 # Runtime container
 FROM alpine:3.17
diff --git a/ecs/README.md b/ecs/README.md
index f5ac2d3..a49d450 100644
--- a/ecs/README.md
+++ b/ecs/README.md
@@ -103,6 +103,12 @@ docker exec -it ejabberd bin/ejabberdctl debug
 
 ## CAPTCHA
 
+### Using mod_ecaptcha
+
+`ejabberd/ecs` includes mod_ecpatcha precompiled from [ejabberd-contrib](https://github.com/processone/ejabberd-contrib/tree/master/mod_ecaptcha).
+
+### Using CAPTCHA scripts
+
 ejabberd includes two example CAPTCHA scripts.
 If you want to use any of them, first install some additional required libraries:
 
diff --git a/ecs/conf/ejabberd.yml b/ecs/conf/ejabberd.yml
index e4603d9..15da445 100644
--- a/ecs/conf/ejabberd.yml
+++ b/ecs/conf/ejabberd.yml
@@ -203,6 +203,8 @@ acme:
    contact: "mailto:example-admin@example.com"
    ca_url: "https://acme-staging-v02.api.letsencrypt.org/directory"
 
+captcha_cmd: mod_ecaptcha
+
 modules:
   mod_adhoc: {}
   mod_admin_extra: {}
@@ -216,6 +218,7 @@ modules:
   mod_client_state: {}
   mod_configure: {}
   mod_disco: {}
+  mod_ecaptcha: {}
   mod_fail2ban: {}
   mod_http_api: {}
   mod_http_upload: