diff --git a/install-python b/install-python
index b2fc46a..3497ca6 100755
--- a/install-python
+++ b/install-python
@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import argparse
+import os
 import shutil
 import sys
 
@@ -11,7 +12,8 @@ ap.add_argument("destination")
 args = ap.parse_args()
 
 with open(args.source) as inf:
-    with open(args.destination, "w") as outf:
+    tmp_dest = args.destination + "." + str(os.getpid())
+    with open(tmp_dest, "w") as outf:
         first_line = inf.readline()
         if first_line.startswith("#!"):
             print("#!", sys.executable, file=outf)
@@ -20,5 +22,6 @@ with open(args.source) as inf:
             outf.write(first_line)
         for line in inf:
             outf.write(line)
+    os.rename(tmp_dest, args.destination)
 
 shutil.copymode(args.source, args.destination)