diff --git a/docs/asio.md b/docs/asio.md
new file mode 100644
index 0000000..b215d9e
--- /dev/null
+++ b/docs/asio.md
@@ -0,0 +1,54 @@
+# ASIO
+
+## Properties
+
+Properties can be dynamically registered to an interface by calling
+`register_property()`. If you need to provide a custom getter or setter for a
+property, it should follow the guidelines in this section.
+
+To return a D-Bus error reply for either GetProperty or SetProperty, throw a
+custom exception derived from `sdbusplus::exception_t`. For the custom
+exception, you can return a well-defined org.freedesktop.DBus.Error
+(https://www.freedesktop.org/software/systemd/man/sd-bus-errors.html#) from the
+`name()` or a custom/arbitrary name. The former will be automatically translated
+into a matching error code
+(https://github.com/systemd/systemd/blob/485c9e19e7ebcd912d5fbf11f40afc62951173f8/src/libsystemd/sd-bus/bus-error.c)
+that can be consumed by the caller, while the latter will always be mapped to
+`EIO`, requiring a `strcmp` to determine the exact error name.
+
+The handler may also throw any exception not derived from
+`sdbusplus::exception_t`, in which case a generic
+org.freedesktop.DBus.Error.InvalidArgs error will be returned to the caller.
+
+### Get Property callback
+
+When registering a property using ASIO methods, the get callback should meet the
+following prototype:
+
+```c++
+PropertyType getHandler(const PropertyType& value);
+```
+
+The first argument is the current value cached in the D-Bus interface (i.e. the
+previously "getted" value, or the initialized value), and the return value is
+returned to the D-Bus caller.
+
+### Set Property callback
+
+When registering a writable property using ASIO methods, the set callback should
+meet the following prototype:
+
+```c++
+bool setHandler(const PropertyType& newValue, PropertyType& value);
+```
+
+The first argument is the new value requested to be set by the D-Bus caller.
+
+The second argument is the actual underlying value contained within the object
+server. If the new value meets the expected constraints, the handler must set
+`value = newValue` to make the set operation take effect and return true. If the
+new value is invalid or cannot be applied for whatever reason, the handler must
+leave `value` unmodified and return false.
+
+If the handler returns false but doesn't throw an exception, a generic
+org.freedesktop.DBus.Error.InvalidArgs error will be returned to the caller.
diff --git a/example/asio-example.cpp b/example/asio-example.cpp
index f113dd3..a83ffea 100644
--- a/example/asio-example.cpp
+++ b/example/asio-example.cpp
@@ -219,17 +219,17 @@
                              [](const int& req, int& propertyValue) {
                                  if (req >= 50)
                                  {
-                                     return -EINVAL;
+                                     return false;
                                  }
                                  propertyValue = req;
-                                 return 1; // success
+                                 return true;
                              });
     iface->register_property(
         "TrailTime", std::string("foo"),
         // custom set
         [](const std::string& req, std::string& propertyValue) {
             propertyValue = req;
-            return 1; // success
+            return true;
         },
         // custom get
         [](const std::string& property) {
diff --git a/example/get-all-properties.cpp b/example/get-all-properties.cpp
index 8b01258..2f1e908 100644
--- a/example/get-all-properties.cpp
+++ b/example/get-all-properties.cpp
@@ -33,7 +33,7 @@
             propertyGoodbyesName, sdbusplus::vtable::property_::emits_change,
             [this](const auto& newPropertyValue, const auto&) {
                 goodbyes_ = newPropertyValue;
-                return 1;
+                return true;
             },
             [this](const auto&) { return goodbyes_; });
 
diff --git a/example/register-property.cpp b/example/register-property.cpp
index 339c0ce..2c3e362 100644
--- a/example/register-property.cpp
+++ b/example/register-property.cpp
@@ -32,7 +32,7 @@
                     sdbusplus::vtable::property_::emits_change,
                     [this](const auto& newPropertyValue, const auto&) {
                         goodbyes_ = newPropertyValue;
-                        return 1;
+                        return true;
                     },
                     [this](const auto&) { return goodbyes_; });
             });
diff --git a/include/sdbusplus/asio/object_server.hpp b/include/sdbusplus/asio/object_server.hpp
index f6db20a..9aed002 100644
--- a/include/sdbusplus/asio/object_server.hpp
+++ b/include/sdbusplus/asio/object_server.hpp
@@ -19,7 +19,6 @@
 #include <list>
 #include <optional>
 #include <set>
-#include <tuple>
 #include <unordered_map>
 
 namespace sdbusplus
@@ -45,7 +44,7 @@
 {
   public:
     virtual ~callback_set() = default;
-    virtual std::tuple<SetPropertyReturnValue, int> call(message_t& m) = 0;
+    virtual SetPropertyReturnValue call(message_t& m) = 0;
     virtual SetPropertyReturnValue set(const std::any& value) = 0;
 };
 
@@ -293,28 +292,22 @@
         value_(value),
         func_(std::move(func))
     {}
-    std::tuple<SetPropertyReturnValue, int> call(message_t& m) override
+    SetPropertyReturnValue call(message_t& m) override
     {
         PropertyType input;
         m.read(input);
-
-        auto oldValue = *value_;
-        auto ret = func_(input, *value_);
-
-        if (ret < 0)
-        {
-            return {SetPropertyReturnValue::fail, ret};
-        }
-        if (oldValue == *value_)
-        {
-            return {SetPropertyReturnValue::sameValueUpdated, ret};
-        }
-        return {SetPropertyReturnValue::valueUpdated, ret};
+        return set_(input);
     }
     SetPropertyReturnValue set(const std::any& value) override
     {
-        auto oldValue = *value_;
-        if (func_(std::any_cast<PropertyType>(value), *value_))
+        return set_(std::any_cast<PropertyType>(value));
+    }
+
+  private:
+    SetPropertyReturnValue set_(const PropertyType& newValue)
+    {
+        PropertyType oldValue = *value_;
+        if (func_(newValue, *value_))
         {
             if (oldValue == *value_)
             {
@@ -465,7 +458,7 @@
                 name, property, vtable::property_::emits_change,
                 [](const PropertyType& req, PropertyType& old) {
                     old = req;
-                    return 1;
+                    return true;
                 },
                 [](const PropertyType& value) { return value; });
         }
@@ -631,26 +624,18 @@
             try
             {
 #endif
-                auto [status, rc] = func->second->call(mesg);
-
-                switch (status)
+                SetPropertyReturnValue status = func->second->call(mesg);
+                if ((status == SetPropertyReturnValue::valueUpdated) ||
+                    (status == SetPropertyReturnValue::sameValueUpdated))
                 {
-                    case SetPropertyReturnValue::sameValueUpdated:
-                    {
-                        return true;
-                    }
-                    case SetPropertyReturnValue::valueUpdated:
+                    if (status != SetPropertyReturnValue::sameValueUpdated)
                     {
                         data->signal_property(property);
-                        return true;
                     }
-                    case SetPropertyReturnValue::fail:
-                    {
-                        sd_bus_error_set_errno(error, rc);
-                        return false;
-                    }
+                    // There shouldn't be any other callbacks that want to
+                    // handle the message so just return a positive integer.
+                    return 1;
                 }
-
 #ifdef __EXCEPTIONS
             }