diff --git a/util/posix/close_stdio.cc b/util/posix/close_stdio.cc
new file mode 100644
index 00000000..8ff59d0a
--- /dev/null
+++ b/util/posix/close_stdio.cc
@@ -0,0 +1,52 @@
+// Copyright 2014 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.
+
+#include "util/posix/close_stdio.h"
+
+#include <fcntl.h>
+#include <paths.h>
+#include <unistd.h>
+
+#include "base/basictypes.h"
+#include "base/files/scoped_file.h"
+#include "base/logging.h"
+#include "base/posix/eintr_wrapper.h"
+
+namespace crashpad {
+
+namespace {
+
+void CloseStdioStream(int desired_fd, int oflag) {
+  base::ScopedFD fd(HANDLE_EINTR(open(_PATH_DEVNULL, oflag)));
+  if (fd == desired_fd) {
+    // Weird, but play along.
+    ignore_result(fd.release());
+  } else {
+    PCHECK(fd.get() >= 0) << "open";
+    PCHECK(HANDLE_EINTR(dup2(fd.get(), desired_fd)) != -1) << "dup2";
+    fd.reset();
+  }
+}
+
+}  // namespace
+
+void CloseStdinAndStdout() {
+  // Open /dev/null for stdin and stdout separately, so that it can be opened
+  // with the correct mode each time. This ensures that attempts to write to
+  // stdin or read from stdout fail with EBADF.
+  CloseStdioStream(STDIN_FILENO, O_RDONLY);
+  CloseStdioStream(STDOUT_FILENO, O_WRONLY);
+}
+
+}  // namespace crashpad
diff --git a/util/posix/close_stdio.h b/util/posix/close_stdio.h
new file mode 100644
index 00000000..9515923b
--- /dev/null
+++ b/util/posix/close_stdio.h
@@ -0,0 +1,42 @@
+// Copyright 2014 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_POSIX_CLOSE_STDIO_H_
+#define CRASHPAD_UTIL_POSIX_CLOSE_STDIO_H_
+
+namespace crashpad {
+
+//! \brief Closes `stdin` and `stdout` by opening `/dev/null` over them.
+//!
+//! It is normally inadvisable to `close()` the three standard input/output
+//! streams, because they occupy special file descriptors. Closing them outright
+//! could result in their file descriptors being reused. This causes problems
+//! for library code (including the standard library) that expects these file
+//! descriptors to have special meaning.
+//!
+//! This function discards the standard input and standard output streams by
+//! opening `/dev/null` and assigning it to their file descriptors, closing
+//! whatever had been at those file descriptors previously.
+//!
+//! `stderr`, the standard error stream, is not closed. It is often useful to
+//! retain the ability to send diagnostic messages to the standard error stream.
+//!
+//! \note This function can only maintain its guarantees in a single-threaded
+//!     process, or in situations where the caller has control of all threads in
+//!     the process.
+void CloseStdinAndStdout();
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_POSIX_CLOSE_STDIO_H_
diff --git a/util/util.gyp b/util/util.gyp
index b3bdf0ff..b950c5db 100644
--- a/util/util.gyp
+++ b/util/util.gyp
@@ -99,6 +99,8 @@
         'numeric/in_range_cast.h',
         'numeric/int128.h',
         'numeric/safe_assignment.h',
+        'posix/close_stdio.cc',
+        'posix/close_stdio.h',
         'posix/drop_privileges.cc',
         'posix/drop_privileges.h',
         'posix/process_info.h',