diff --git a/src/exception.cpp b/src/exception.cpp
index 640454a..4fa5135 100644
--- a/src/exception.cpp
+++ b/src/exception.cpp
@@ -19,6 +19,11 @@
     return EIO;
 }
 
+int generated_exception::get_errno() const noexcept
+{
+    return EIO;
+}
+
 SdBusError::SdBusError(int error, const char* prefix, SdBusInterface* intf) :
     error(SD_BUS_ERROR_NULL), intf(intf)
 {