diff --git a/rattail/files.py b/rattail/files.py
index 54d3b78b81bba29a5e66fe8c256c79245d2770ac..59b962454dbac577e60cdafe9a26df2c9550e436 100644
--- a/rattail/files.py
+++ b/rattail/files.py
@@ -34,6 +34,7 @@ import os.path
 import shutil
 import lockfile
 import tempfile
+import errno
 from datetime import datetime
 
 import pkg_resources
@@ -113,7 +114,7 @@ def locking_copy(src, dst, timeout=None):
         shutil.copy(src, dst)
 
 
-def locking_copy_test(src, dst):
+def locking_copy_test(src, destdir):
     """
     Implements a "locking" version of the standard library's
     :func:`python:shutil.copy()` function.
@@ -127,19 +128,22 @@ def locking_copy_test(src, dst):
     :param src: Path to the source file.
     :type src: string
 
-    :param dst: Path to the destination file (or directory).
-    :type dst: string
+    :param destdir: Path to the destination directory.
+    :type destdir: string
     """
-    if os.path.isdir(dst):
-        fn = os.path.basename(src)
-        dst = os.path.join(dst, fn)
-
+    fn = os.path.basename(src)
+    dst = os.path.join(destdir, fn)
     lockdir = '{0}.lock'.format(dst)
+
+    # Attempt to create the lock dir.  We ignore "file exists" error here since
+    # it's possible this function may be called mutliple times as part of a
+    # filemon retry strategy.
     try:
         os.mkdir(lockdir)
     except OSError as error:
-        if error.errno != 17:   # file exists
+        if error.errno != errno.EEXIST:
             raise
+
     shutil.copy(src, dst)
     os.rmdir(lockdir)