diff --git a/picard/util/astrcmp.c b/picard/util/_astrcmp.c
similarity index 99%
rename from picard/util/astrcmp.c
rename to picard/util/_astrcmp.c
index 95641b4dc..7b8dd1803 100644
--- a/picard/util/astrcmp.c
+++ b/picard/util/_astrcmp.c
@@ -180,7 +180,7 @@ static struct PyModuleDef AstrcmpModule =
 };
 
 PyMODINIT_FUNC 
-PyInit_astrcmp(void)
+PyInit__astrcmp(void)
 {
     return PyModule_Create(&AstrcmpModule);
-}
\ No newline at end of file
+}
diff --git a/picard/util/astrcmp.py b/picard/util/astrcmp.py
new file mode 100644
index 000000000..ff07cae6a
--- /dev/null
+++ b/picard/util/astrcmp.py
@@ -0,0 +1,36 @@
+# http://hetland.org/coding/python/levenshtein.py
+
+# This is a straightforward implementation of a well-known algorithm, and thus
+# probably shouldn't be covered by copyright to begin with. But in case it is,
+# the author (Magnus Lie Hetland) has, to the extent possible under law,
+# dedicated all copyright and related and neighboring rights to this software
+# to the public domain worldwide, by distributing it under the CC0 license,
+# version 1.0. This software is distributed without any warranty. For more
+# information, see <http://creativecommons.org/publicdomain/zero/1.0>
+
+
+def astrcmp_py(a,b):
+    "Calculates the Levenshtein distance between a and b."
+    n, m = len(a), len(b)
+    if n > m:
+        # Make sure n <= m, to use O(min(n,m)) space
+        a,b = b,a
+        n,m = m,n
+
+    current = range(n+1)
+    for i in range(1,m+1):
+        previous, current = current, [i]+[0]*n
+        for j in range(1,n+1):
+            add, delete = previous[j]+1, current[j-1]+1
+            change = previous[j-1]
+            if a[j-1] != b[i-1]:
+                change = change + 1
+            current[j] = min(add, delete, change)
+
+    return 1.0 - float(current[n]) / max(m, n)
+
+
+try:
+    from picard.util._astrcmp import astrcmp
+except ImportError:
+    astrcmp = astrcmp_py
diff --git a/setup.py b/setup.py
index 2687c8818..a537e1975 100755
--- a/setup.py
+++ b/setup.py
@@ -35,7 +35,7 @@ from distutils.dist import Distribution
 from distutils.spawn import find_executable
 
 ext_modules = [
-    Extension('picard.util.astrcmp', sources=['picard/util/astrcmp.c']),
+    Extension('picard.util._astrcmp', sources=['picard/util/_astrcmp.c']),
 ]
 
 py2app_exclude_modules = [