diff --git a/contrib/packaging/wix/help.wxs b/contrib/packaging/wix/help.wxs
--- a/contrib/packaging/wix/help.wxs
+++ b/contrib/packaging/wix/help.wxs
@@ -49,6 +49,7 @@
             <File Id="internals.config.txt"       Name="config.txt" />
             <File Id="internals.extensions.txt"   Name="extensions.txt" />
             <File Id="internals.linelog.txt"      Name="linelog.txt" />
+            <File Id="internals.mergestate.txt"   Name="mergestate.txt" />
             <File Id="internals.requirements.txt" Name="requirements.txt" />
             <File Id="internals.revlogs.txt"      Name="revlogs.txt" />
             <File Id="internals.wireprotocol.txt" Name="wireprotocol.txt" />
diff --git a/tests/test-help.t b/tests/test-help.t
--- a/tests/test-help.t
+++ b/tests/test-help.t
@@ -1078,6 +1078,7 @@
        changegroups  Changegroups
        config        Config Registrar
        extensions    Extension API
+       mergestate    Mergestate
        requirements  Repository Requirements
        revlogs       Revision Logs
        wireprotocol  Wire Protocol
@@ -3425,6 +3426,13 @@
   Extension API
   </td></tr>
   <tr><td>
+  <a href="/help/internals.mergestate">
+  mergestate
+  </a>
+  </td><td>
+  Mergestate
+  </td></tr>
+  <tr><td>
   <a href="/help/internals.requirements">
   requirements
   </a>