diff --git a/ipc/glue/ProtocolUtils.h b/ipc/glue/ProtocolUtils.h
index 01af0dc52de2..48c2b75c545b 100644
--- a/ipc/glue/ProtocolUtils.h
+++ b/ipc/glue/ProtocolUtils.h
@@ -56,6 +56,12 @@ class NeckoParent;
 
 namespace ipc {
 
+#ifdef XP_WIN
+const base::ProcessHandle kInvalidProcessHandle = INVALID_HANDLE_VALUE;
+#else
+const base::ProcessHandle kInvalidProcessHandle = -1;
+#endif
+
 class ProtocolFdMapping;
 class ProtocolCloneContext;
 
diff --git a/ipc/ipdl/ipdl/lower.py b/ipc/ipdl/ipdl/lower.py
index f408ec2d600d..dcfac3ca8903 100644
--- a/ipc/ipdl/ipdl/lower.py
+++ b/ipc/ipdl/ipdl/lower.py
@@ -2884,6 +2884,8 @@ class _GenerateProtocolActorCode(ipdl.ast.Visitor):
                              [ ExprVar.THIS ]) ]),
                 ExprMemberInit(p.lastActorIdVar(),
                                [ p.actorIdInit(self.side) ]),
+                ExprMemberInit(p.otherProcessVar(),
+                               [ ExprVar('ipc::kInvalidProcessHandle') ]),
                 ExprMemberInit(p.lastShmemIdVar(),
                                [ p.shmemIdInit(self.side) ]),
                 ExprMemberInit(p.stateVar(),