diff --git a/src/mem/ruby/common/MachineID.hh b/src/mem/ruby/common/MachineID.hh
index 0ad898959..a28b0af7e 100644
--- a/src/mem/ruby/common/MachineID.hh
+++ b/src/mem/ruby/common/MachineID.hh
@@ -37,6 +37,10 @@
 
 struct MachineID
 {
+    MachineID() : type(MachineType_NULL), num(0) { }
+    MachineID(MachineType mach_type, NodeID node_id)
+        : type(mach_type), num(node_id) { }
+
     MachineType type;
     //! range: 0 ... number of this machine's components in system - 1
     NodeID num;