diff --git a/lib/glacier/status/error_or.h b/lib/glacier/status/error_or.h
index 38c00c8..cbdc158 100644
--- a/lib/glacier/status/error_or.h
+++ b/lib/glacier/status/error_or.h
@@ -10,6 +10,8 @@ class ErrorOr {
   ErrorOr() = delete;
   ErrorOr(const ErrorOr&) = delete;
   ErrorOr(ErrorOr&&) = delete;
+  // FIXME: Do we have to call ~T manually here.
+  ~ErrorOr() {}
 
   ErrorOr(ErrorCode code) : error_(code), ok_(false) {}
   ErrorOr(const T& obj) : obj_(obj), ok_(true) {}
diff --git a/lib/mammoth/include/mammoth/process.h b/lib/mammoth/include/mammoth/process.h
index 477f0fb..a331422 100644
--- a/lib/mammoth/include/mammoth/process.h
+++ b/lib/mammoth/include/mammoth/process.h
@@ -1,7 +1,8 @@
 #pragma once
 
+#include <glacier/status/error_or.h>
 #include <stdint.h>
 
 #include "mammoth/channel.h"
 
-uint64_t SpawnProcessFromElfRegion(uint64_t program, Channel& local);
+glcr::ErrorOr<Channel> SpawnProcessFromElfRegion(uint64_t program);
diff --git a/lib/mammoth/src/process.cpp b/lib/mammoth/src/process.cpp
index e199088..068cd88 100644
--- a/lib/mammoth/src/process.cpp
+++ b/lib/mammoth/src/process.cpp
@@ -95,8 +95,8 @@ uint64_t LoadElfProgram(uint64_t base, uint64_t as_cap) {
 
 }  // namespace
 
-uint64_t SpawnProcessFromElfRegion(uint64_t program, Channel& local) {
-  Channel foreign;
+glcr::ErrorOr<Channel> SpawnProcessFromElfRegion(uint64_t program) {
+  Channel local, foreign;
   check(CreateChannels(local, foreign));
 
   uint64_t proc_cap;
@@ -134,5 +134,5 @@ uint64_t SpawnProcessFromElfRegion(uint64_t program, Channel& local) {
 #endif
   check(ZThreadStart(thread_cap, entry_point, foreign_port_id, 0));
 
-  return glcr::OK;
+  return local;
 }
diff --git a/sys/yellowstone/yellowstone.cpp b/sys/yellowstone/yellowstone.cpp
index 1265e88..fd898a6 100644
--- a/sys/yellowstone/yellowstone.cpp
+++ b/sys/yellowstone/yellowstone.cpp
@@ -17,8 +17,11 @@ uint64_t main(uint64_t port_cap) {
   uint64_t vaddr;
   check(ZAddressSpaceMap(gSelfVmasCap, 0, gBootDenaliVmmoCap, &vaddr));
 
-  Channel local;
-  check(SpawnProcessFromElfRegion(vaddr, local));
+  auto local_or = SpawnProcessFromElfRegion(vaddr);
+  if (!local_or) {
+    check(local_or.error());
+  }
+  Channel local = local_or.value();
 
   DenaliClient client(local);
   GptReader reader(client);