diff --git a/pydir/build-pnacl-ir.py b/pydir/build-pnacl-ir.py
new file mode 100755
index 0000000..67dbefd
--- /dev/null
+++ b/pydir/build-pnacl-ir.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python2
+
+import argparse
+import os
+import sys
+import tempfile
+from utils import shellcmd
+
+if __name__ == '__main__':
+    argparser = argparse.ArgumentParser()
+    argparser.add_argument('cfile', nargs='+', type=str,
+        help='C file(s) to convert')
+    argparser.add_argument('--nacl_sdk_root', nargs='?', type=str,
+        help='Path to NACL_SDK_ROOT')
+    argparser.add_argument('--dir', nargs='?', type=str, default='.',
+                           help='Output directory')
+    argparser.add_argument('--disable-verify', action='store_true')
+    args = argparser.parse_args()
+
+    nacl_sdk_root = os.environ.get('NACL_SDK_ROOT', None)
+    if args.nacl_sdk_root:
+        nacl_sdk_root = os.path.expanduser(args.nacl_sdk_root)
+
+    if not nacl_sdk_root or not os.path.exists(nacl_sdk_root):
+        print '''\
+Please set the NACL_SDK_ROOT environment variable or pass the path through
+--nacl_sdk_root to point to a valid Native Client SDK installation.'''
+        sys.exit(1)
+
+    includes_path = os.path.join(nacl_sdk_root, 'include')
+    toolchain_path = os.path.join(nacl_sdk_root, 'toolchain', 'linux_pnacl')
+    clang_path = os.path.join(toolchain_path, 'bin64', 'pnacl-clang')
+    opt_path = os.path.join(toolchain_path, 'host_x86_64', 'bin', 'opt')
+
+    tempdir = tempfile.mkdtemp()
+
+    for cname in args.cfile:
+        basename = os.path.splitext(cname)[0]
+        llname = os.path.join(tempdir, basename + '.ll')
+        pnaclname = basename + '.pnacl.ll'
+        pnaclname = os.path.join(args.dir, pnaclname)
+
+        shellcmd(clang_path + ' -I{0} -c {1} -o {2}'.format(
+            includes_path, cname, llname))
+        shellcmd(opt_path +
+            ' -O2 -pnacl-abi-simplify-preopt -pnacl-abi-simplify-postopt' +
+            ('' if args.disable_verify else
+             ' -verify-pnaclabi-module -verify-pnaclabi-functions') +
+            ' -pnaclabi-allow-debug-metadata -disable-simplify-libcalls'
+            ' {0} -S -o {1}'.format(llname, pnaclname))