diff --git a/sdbusplus/bus.hpp.in b/sdbusplus/bus.hpp.in
index 9e7476b..e01d1f2 100644
--- a/sdbusplus/bus.hpp.in
+++ b/sdbusplus/bus.hpp.in
@@ -234,6 +234,10 @@
     }
 
     /** @brief Perform a message call.
+     *         Errors generated by this call come from underlying dbus
+     *         related errors *AND* from any method call that results
+     *         in a METHOD_ERROR. This means you do not need to check
+     *         is_method_error() on the returned message.
      *
      *  @param[in] m - The method_call message.
      *  @param[in] timeout_us - The timeout for the method call.