diff --git a/src/core/system.cpp b/src/core/system.cpp
index 076f50cf3..6beef00e5 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -278,6 +278,9 @@ bool System::DoState(StateWrapper& sw)
   if (!sw.DoMarker("MDEC") || !m_mdec->DoState(sw))
     return false;
 
+  if (!sw.DoMarker("SIO") || !m_sio->DoState(sw))
+    return false;
+
   return !sw.HasError();
 }