diff --git a/ChangeLog b/ChangeLog
index cb5af252..2e4f4008 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -41,6 +41,7 @@
           (thanks to Martin Boeker).
 - Added DOM support and a 'get' command.
 - Added 'totals.py' sample extension.
+- Added extension list to the 'help' command.
 
 ------ old release ---------------------------
 
diff --git a/src/commands/CmdHelp.cpp b/src/commands/CmdHelp.cpp
index c8a01abc..e1292354 100644
--- a/src/commands/CmdHelp.cpp
+++ b/src/commands/CmdHelp.cpp
@@ -29,7 +29,7 @@
 #include <iostream>
 
 ////////////////////////////////////////////////////////////////////////////////
-int CmdHelpUsage ()
+int CmdHelpUsage (const Extensions& extensions)
 {
   // TODO This is going to need more formatting.
   // TODO Align the arg types?
@@ -65,8 +65,19 @@ int CmdHelpUsage ()
             << "       timew track <interval> [<tag> ...]\n"
             << "       timew untag @<id> [@<id> ...] <tag> [<tag> ...]\n"
             << "       timew week [<interval>] [<tag> ...]\n"
-            << '\n'
-            << "Additional help:\n"
+            << '\n';
+
+  if (extensions.all ().size ())
+  {
+    std::cout << "Extensions (extensions do not provide help):\n";
+
+    for (auto& ext : extensions.all ())
+      std::cout << "       " << File (ext).name () << '\n';
+
+    std::cout << '\n';
+  }
+
+  std::cout << "Additional help:\n"
             << "       timew help <command>\n"
             << "       timew help interval\n"
             << "       timew help hints\n"
@@ -104,7 +115,9 @@ int CmdHelpUsage ()
 //
 // Strict 80-character limit.
 // Provide examples where appropriate - enough to cover all uses.
-int CmdHelp (const CLI& cli)
+int CmdHelp (
+  const CLI& cli,
+  const Extensions& extensions)
 {
   auto words = cli.getWords ();
   if (words.size ())
@@ -906,7 +919,7 @@ int CmdHelp (const CLI& cli)
     return 0;
   }
 
-  return CmdHelpUsage ();
+  return CmdHelpUsage (extensions);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/commands/commands.h b/src/commands/commands.h
index 26c48b6f..2758dc76 100644
--- a/src/commands/commands.h
+++ b/src/commands/commands.h
@@ -43,8 +43,8 @@ int CmdExtensions    (            Rules&,            const Extensions&);
 int CmdFill          (const CLI&, Rules&, Database&                   );
 int CmdGaps          (const CLI&, Rules&, Database&                   );
 int CmdGet           (const CLI&, Rules&, Database&                   );
-int CmdHelpUsage     (                                                );
-int CmdHelp          (const CLI&                                      );
+int CmdHelpUsage     (                               const Extensions&);
+int CmdHelp          (const CLI&,                    const Extensions&);
 int CmdJoin          (const CLI&, Rules&, Database&                   );
 int CmdLengthen      (const CLI&, Rules&, Database&                   );
 int CmdMove          (const CLI&, Rules&, Database&                   );
diff --git a/src/init.cpp b/src/init.cpp
index 667200b8..5443fcf1 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -268,7 +268,7 @@ int dispatchCommand (
 */
     else if (command == "gaps")        status = CmdGaps          (cli, rules, database            );
     else if (command == "get")         status = CmdGet           (cli, rules, database            );
-    else if (command == "help")        status = CmdHelp          (cli                             );
+    else if (command == "help")        status = CmdHelp          (cli,                  extensions);
     else if (command == "join")        status = CmdJoin          (cli, rules, database            );
     else if (command == "lengthen")    status = CmdLengthen      (cli, rules, database            );
     else if (command == "month")       status = CmdChartMonth    (cli, rules, database            );