diff --git a/test/multiprocess.h b/test/multiprocess.h
index 9a221bb3..61df98b5 100644
--- a/test/multiprocess.h
+++ b/test/multiprocess.h
@@ -15,6 +15,7 @@
 #ifndef CRASHPAD_TEST_MULTIPROCESS_H_
 #define CRASHPAD_TEST_MULTIPROCESS_H_
 
+#include <stdint.h>
 #include <sys/types.h>
 
 #include "base/macros.h"
@@ -28,6 +29,12 @@ namespace internal {
 struct MultiprocessInfo;
 }  // namespace internal
 
+#if defined(OS_FUCHSIA)
+using ReturnCodeType = int64_t;
+#else
+using ReturnCodeType = int;
+#endif
+
 //! \brief Manages a multiprocess test.
 //!
 //! These tests are `fork()`-based. The parent and child processes are able to
@@ -76,7 +83,7 @@ class Multiprocess {
 
   //! \brief Sets the expected termination reason and code.
   //!
-  //! The default expected termination reasaon is
+  //! The default expected termination reason is
   //! TerminationReason::kTerminationNormal, and the default expected
   //! termination code is `EXIT_SUCCESS` (`0`).
   //!
@@ -91,7 +98,8 @@ class Multiprocess {
   //!     TerminationReason::kTerminationSignal, this is the signal that is
   //!     expected to kill the child. On Linux platforms, SIG_DFL will be
   //!     installed for \a code in the child process.
-  void SetExpectedChildTermination(TerminationReason reason, int code);
+  void SetExpectedChildTermination(TerminationReason reason,
+                                   ReturnCodeType code);
 
 #if !defined(OS_WIN)
   //! \brief Sets termination reason and code appropriately for a child that
@@ -211,7 +219,7 @@ class Multiprocess {
   virtual void MultiprocessChild() = 0;
 
   internal::MultiprocessInfo* info_;
-  int code_;
+  ReturnCodeType code_;
   TerminationReason reason_;
 
   DISALLOW_COPY_AND_ASSIGN(Multiprocess);
diff --git a/test/multiprocess_exec_fuchsia.cc b/test/multiprocess_exec_fuchsia.cc
index 9c68b7fd..eff522b0 100644
--- a/test/multiprocess_exec_fuchsia.cc
+++ b/test/multiprocess_exec_fuchsia.cc
@@ -87,7 +87,7 @@ void Multiprocess::Run() {
 }
 
 void Multiprocess::SetExpectedChildTermination(TerminationReason reason,
-                                               int code) {
+                                               ReturnCodeType code) {
   EXPECT_EQ(info_, nullptr)
       << "SetExpectedChildTermination() must be called before Run()";
   reason_ = reason;
@@ -95,7 +95,15 @@ void Multiprocess::SetExpectedChildTermination(TerminationReason reason,
 }
 
 void Multiprocess::SetExpectedChildTerminationBuiltinTrap() {
-  SetExpectedChildTermination(kTerminationNormal, -1);
+  // TODO(scottmg): Once
+  // https://fuchsia-review.googlesource.com/c/fuchsia/+/256771 lands, remove
+  // this #ifdef, and always use ZX_TASK_RETCODE_EXCEPTION_KILL.
+#if defined(ZX_TASK_RETCODE_EXCEPTION_KILL)
+  constexpr ReturnCodeType kExpectedReturnCode = ZX_TASK_RETCODE_EXCEPTION_KILL;
+#else
+  constexpr ReturnCodeType kExpectedReturnCode = -1;
+#endif
+  SetExpectedChildTermination(kTerminationNormal, kExpectedReturnCode);
 }
 
 Multiprocess::~Multiprocess() {
diff --git a/test/multiprocess_exec_win.cc b/test/multiprocess_exec_win.cc
index 38978186..b75f8f57 100644
--- a/test/multiprocess_exec_win.cc
+++ b/test/multiprocess_exec_win.cc
@@ -58,7 +58,7 @@ void Multiprocess::Run() {
 }
 
 void Multiprocess::SetExpectedChildTermination(TerminationReason reason,
-                                               int code) {
+                                               ReturnCodeType code) {
   EXPECT_EQ(info_, nullptr)
       << "SetExpectedChildTermination() must be called before Run()";
   reason_ = reason;
diff --git a/test/multiprocess_posix.cc b/test/multiprocess_posix.cc
index 2e0c3856..d2de3184 100644
--- a/test/multiprocess_posix.cc
+++ b/test/multiprocess_posix.cc
@@ -154,7 +154,7 @@ void Multiprocess::Run() {
 }
 
 void Multiprocess::SetExpectedChildTermination(TerminationReason reason,
-                                               int code) {
+                                               ReturnCodeType code) {
   EXPECT_EQ(info_, nullptr)
       << "SetExpectedChildTermination() must be called before Run()";
   reason_ = reason;