diff --git a/lib_standalone/ModuleLibrary.cpp b/lib_standalone/ModuleLibrary.cpp
new file mode 100644
index 000000000..eae248dd4
--- /dev/null
+++ b/lib_standalone/ModuleLibrary.cpp
@@ -0,0 +1,31 @@
+/*
+ * EMS-ESP - https://github.com/emsesp/EMS-ESP
+ * Copyright 2020-2024  Paul Derbyshire
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <Arduino.h>
+
+#include <emsesp.h>
+
+void ModuleLibrary::list(JsonObject output) {};
+
+void ModuleLibrary::loop() {};
+
+void ModuleLibrary::start(emsesp::EMSESP * emsesp_main, bool test_mode) {};
+
+bool ModuleLibrary::enable(const char * key, const char * license, bool enable) {
+    return true;
+};
diff --git a/lib_standalone/ModuleLibrary.h b/lib_standalone/ModuleLibrary.h
index 8d77f0e6e..e1d27f236 100644
--- a/lib_standalone/ModuleLibrary.h
+++ b/lib_standalone/ModuleLibrary.h
@@ -38,12 +38,10 @@ class ModuleLibrary {
         std::unique_ptr<Module> module;
     };
 
-    void start(emsesp::EMSESP * emsesp_main, bool test_mode = false) {};
-    void loop() {};
-    void list(JsonObject output) {};
-    bool enable(const char * key, const char * license, bool enable) {
-        return true;
-    };
+    void start(emsesp::EMSESP * emsesp_main, bool test_mode = false);
+    void loop();
+    void list(JsonObject output);
+    bool enable(const char * key, const char * license, bool enable);
 
     static uuid::log::Logger logger_;