diff --git a/Lib/fontTools/varLib/interpolatable.py b/Lib/fontTools/varLib/interpolatable.py
index a9583a18d..d31f803e2 100644
--- a/Lib/fontTools/varLib/interpolatable.py
+++ b/Lib/fontTools/varLib/interpolatable.py
@@ -16,12 +16,12 @@ import itertools
 import sys
 
 def _rot_list(l, k):
-	"""Rotate list by k items forward.  Ie. item at position 0 will be
-	at position k in returned list.  Negative k is allowed."""
-	n = len(l)
-	k %= n
-	if not k: return l
-	return l[n-k:] + l[:n-k]
+    """Rotate list by k items forward.  Ie. item at position 0 will be
+    at position k in returned list.  Negative k is allowed."""
+    n = len(l)
+    k %= n
+    if not k: return l
+    return l[n-k:] + l[:n-k]
 
 
 class PerContourPen(BasePen):