diff --git a/example/asio-example.cpp b/example/asio-example.cpp
index 31b55f2..354c7b0 100644
--- a/example/asio-example.cpp
+++ b/example/asio-example.cpp
@@ -17,6 +17,11 @@
     return ++test;
 }
 
+int voidBar(void)
+{
+    return 42;
+}
+
 int main()
 {
     using GetSubTreeType = std::vector<std::pair<
@@ -121,6 +126,8 @@
 
     iface->register_method("TestMethodWithMessage", methodWithMessage);
 
+    iface->register_method("VoidFunctionReturnsInt", voidBar);
+
     iface->initialize();
     iface->set_property("int", 45);
     io.run();
diff --git a/sdbusplus/utility/type_traits.hpp b/sdbusplus/utility/type_traits.hpp
index fb6f0b6..2d60972 100644
--- a/sdbusplus/utility/type_traits.hpp
+++ b/sdbusplus/utility/type_traits.hpp
@@ -38,6 +38,7 @@
 template <typename T>
 struct get_first_arg
 {
+    using type = void;
 };
 
 template <typename FirstArg, typename... Rest>