diff --git a/libc/bionic/legacy_32_bit_support.cpp b/libc/bionic/legacy_32_bit_support.cpp
index d7ccdb9..411daa0 100644
--- a/libc/bionic/legacy_32_bit_support.cpp
+++ b/libc/bionic/legacy_32_bit_support.cpp
@@ -27,6 +27,7 @@
  */
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdarg.h>
 #include <sys/resource.h>
 #include <sys/types.h>
@@ -86,6 +87,11 @@
   return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
 }
 
+// There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
+int fallocate(int fd, int mode, off_t offset, off_t length) {
+  return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));
+}
+
 // There is no getrlimit64 system call, so we need to use prlimit64.
 int getrlimit64(int resource, rlimit64* limits64) {
   return prlimit64(0, resource, NULL, limits64);
diff --git a/libc/bionic/posix_fallocate.cpp b/libc/bionic/posix_fallocate.cpp
new file mode 100644
index 0000000..bdc1636
--- /dev/null
+++ b/libc/bionic/posix_fallocate.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <fcntl.h>
+
+#include "private/ErrnoRestorer.h"
+
+int posix_fallocate(int fd, off_t offset, off_t length) {
+  ErrnoRestorer errno_restorer;
+  return (fallocate(fd, 0, offset, length) == 0) ? 0 : errno;
+}
+
+int posix_fallocate64(int fd, off64_t offset, off64_t length) {
+  ErrnoRestorer errno_restorer;
+  return (fallocate64(fd, 0, offset, length) == 0) ? 0 : errno;
+}