diff --git a/offlineimap/utils/stacktrace.py b/offlineimap/utils/stacktrace.py
index 007d7ec..ba6bf4f 100644
--- a/offlineimap/utils/stacktrace.py
+++ b/offlineimap/utils/stacktrace.py
@@ -8,18 +8,16 @@ import traceback
 
 
 def dump(out):
-	""" Dumps current stack trace into I/O object 'out' """
-	id2name = {}
-	for th in threading.enumerate():
-		id2name[th.ident] = th.name
-	n = 0
-	for i, stack in list(sys._current_frames().items()):
-		out.write ("\n# Thread #%d (id=%d), %s\n" % \
-		  (n, i, id2name[i]))
-		n = n + 1
-		for f, lno, name, line in traceback.extract_stack (stack):
-			out.write ('File: "%s", line %d, in %s' % \
-			  (f, lno, name))
-			if line:
-				out.write (" %s" % (line.strip()))
-			out.write ("\n")
+    """ Dumps current stack trace into I/O object 'out' """
+    id2name = {}
+    for th in threading.enumerate():
+        id2name[th.ident] = th.name
+    n = 0
+    for i, stack in list(sys._current_frames().items()):
+        out.write("\n# Thread #%d (id=%d), %s\n" % (n, i, id2name[i]))
+        n = n + 1
+        for f, lno, name, line in traceback.extract_stack(stack):
+            out.write('File: "%s", line %d, in %s' % (f, lno, name))
+            if line:
+                out.write(" %s" % (line.strip()))
+            out.write("\n")