diff --git a/README.md b/README.md
index e6c997e..1da2ce9 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,7 @@ CONFIGURATION
 Configurable options:
 - --storage.tsdb.retention.time via `$ps_retention_time`
 - --storage.tsdb.retention.size via `$ps_retention_size`
+- --storage.tsdb.wal-segment-size via `ps_wal_seg_size`
 - authentication user via `$ps_auth_user`
 - authentication password via `$ps_auth_pass`
 - web authentication password via `$ps_web_pass` ( different format required)
diff --git a/doc/file.README.html b/doc/file.README.html
index b0d318a..79d8ab3 100644
--- a/doc/file.README.html
+++ b/doc/file.README.html
@@ -92,7 +92,7 @@
 <p>manage service</p>
 </li></ul>
 
-<p>Configurable options: - –storage.tsdb.retention.time via <code>$ps_retention_time</code> - –storage.tsdb.retention.size via <code>$ps_retention_size</code> - authentication user via <code>$ps_auth_user</code> - authentication password via <code>$ps_auth_pass</code> - web authentication password via <code>$ps_web_pass</code> ( different format required)</p>
+<p>Configurable options: - –storage.tsdb.retention.time via <code>$ps_retention_time</code> - –storage.tsdb.retention.size via <code>$ps_retention_size</code> - –storage.tsdb.wal-segment-size via <code>ps_wal_seg_size</code> - authentication user via <code>$ps_auth_user</code> - authentication password via <code>$ps_auth_pass</code> - web authentication password via <code>$ps_web_pass</code> ( different format required)</p>
 
 <h2 id="label-Repo+Documentation">Repo Documentation</h2>
 
diff --git a/doc/index.html b/doc/index.html
index f094e77..923bcc0 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -92,7 +92,7 @@
 <p>manage service</p>
 </li></ul>
 
-<p>Configurable options: - –storage.tsdb.retention.time via <code>$ps_retention_time</code> - –storage.tsdb.retention.size via <code>$ps_retention_size</code> - authentication user via <code>$ps_auth_user</code> - authentication password via <code>$ps_auth_pass</code> - web authentication password via <code>$ps_web_pass</code> ( different format required)</p>
+<p>Configurable options: - –storage.tsdb.retention.time via <code>$ps_retention_time</code> - –storage.tsdb.retention.size via <code>$ps_retention_size</code> - –storage.tsdb.wal-segment-size via <code>ps_wal_seg_size</code> - authentication user via <code>$ps_auth_user</code> - authentication password via <code>$ps_auth_pass</code> - web authentication password via <code>$ps_web_pass</code> ( different format required)</p>
 
 <h2 id="label-Repo+Documentation">Repo Documentation</h2>
 
diff --git a/doc/puppet_classes/prometheus_cd_3A_3Aparams.html b/doc/puppet_classes/prometheus_cd_3A_3Aparams.html
index 3ab5fc0..28973b8 100644
--- a/doc/puppet_classes/prometheus_cd_3A_3Aparams.html
+++ b/doc/puppet_classes/prometheus_cd_3A_3Aparams.html
@@ -358,6 +358,24 @@
         &mdash;
         <div class='inline'>
 <p>tsdb retention size</p>
+</div>
+      
+    </li>
+  
+    <li>
+      
+        <span class='name'>ps_wal_seg_size</span>
+      
+      
+        <span class='type'>(<tt>String</tt>)</span>
+      
+      
+        <em class="default">(defaults to: <tt>&#39;50MB&#39;</tt>)</em>
+      
+      
+        &mdash;
+        <div class='inline'>
+<p>WAL segment size</p>
 </div>
       
     </li>
@@ -373,7 +391,6 @@
         <pre class="lines">
 
 
-20
 21
 22
 23
@@ -421,10 +438,12 @@
 65
 66
 67
-68</pre>
+68
+69
+70</pre>
       </td>
       <td>
-        <pre class="code"><span class="info file"># File 'manifests/params.pp', line 20</span>
+        <pre class="code"><span class="info file"># File 'manifests/params.pp', line 21</span>
 
 class prometheus_cd::params (
 
@@ -451,6 +470,7 @@ class prometheus_cd::params (
   # storage
   String $ps_retention_time     = &#39;15d&#39;,
   String $ps_retention_size     = &#39;20GB&#39;,
+  String $ps_wal_seg_size       = &#39;50MB&#39;,
 
 ) {
   # defaults
diff --git a/manifests/params.pp b/manifests/params.pp
index e655d6e..bfcd81e 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -16,6 +16,7 @@
 # @param [String] ps_web_pass the password for web authentication
 # @param [String] ps_retention_time tsdb retention time
 # @param [String] ps_retention_size tsdb retention size
+# @param [String] ps_wal_seg_size WAL segment size
 ##############################################################################
 class prometheus_cd::params (
 
@@ -42,6 +43,7 @@ class prometheus_cd::params (
   # storage
   String $ps_retention_time     = '15d',
   String $ps_retention_size     = '20GB',
+  String $ps_wal_seg_size       = '50MB',
 
 ) {
   # defaults
diff --git a/templates/override.conf.erb b/templates/override.conf.erb
index be35f1a..0766512 100644
--- a/templates/override.conf.erb
+++ b/templates/override.conf.erb
@@ -9,6 +9,7 @@ ExecStart=/usr/bin/prometheus \
   --storage.tsdb.path=/var/lib/prometheus \
   --storage.tsdb.retention.time=<%= @ps_retention_time %> \
   --storage.tsdb.retention.size=<%= @ps_retention_size %> \
+  --storage.tsdb.wal-segment-size=<%= @psps_wal_seg_size %> \
   --web.enable-remote-write-receiver \
   --web.enable-lifecycle \
   --storage.tsdb.wal-compression
\ No newline at end of file