diff --git a/util/BUILD.gn b/util/BUILD.gn
index d3578dd4..21e6fed2 100644
--- a/util/BUILD.gn
+++ b/util/BUILD.gn
@@ -379,6 +379,7 @@ static_library("util") {
 
   if (crashpad_is_fuchsia) {
     sources += [
+      "fuchsia/system_exception_port_key.h",
       "fuchsia/koid_utilities.cc",
       "fuchsia/koid_utilities.h",
       "fuchsia/scoped_task_suspend.cc",
diff --git a/util/fuchsia/system_exception_port_key.h b/util/fuchsia/system_exception_port_key.h
new file mode 100644
index 00000000..0bbae690
--- /dev/null
+++ b/util/fuchsia/system_exception_port_key.h
@@ -0,0 +1,27 @@
+// Copyright 2018 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_UTIL_FUCHSIA_EXCEPTION_PORT_KEY_H_
+#define CRASHPAD_UTIL_FUCHSIA_EXCEPTION_PORT_KEY_H_
+
+namespace crashpad {
+
+//! \brief The key used in `zx_task_bind_exception_port()` and packet
+//!     processing. This matches the value that Zircon's `devmgr` and
+//!     `crashlogger` use for interoperability, for now.
+constexpr uint64_t kSystemExceptionPortKey = 1166444u;
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_FUCHSIA_EXCEPTION_PORT_KEY_H_