diff --git a/src/fix.py b/src/fix.py
index e0662d1a0..84f919e4c 100644
--- a/src/fix.py
+++ b/src/fix.py
@@ -74,6 +74,7 @@ def reversed(L):
 
 def window(L, size):
     """Returns a sliding 'window' through the list L of size size."""
+    assert not isinstance(L, int), 'Argument order swapped: window(L, size)'
     if size < 1:
         raise ValueError, 'size <= 0 disallowed.'
     for i in xrange(len(L) - (size-1)):
diff --git a/src/utils.py b/src/utils.py
index 95d57f048..7d3c22809 100755
--- a/src/utils.py
+++ b/src/utils.py
@@ -453,7 +453,9 @@ def mktemp(suffix=''):
     return sha.sha(s + str(time.time())).hexdigest() + suffix
 
 def itersplit(isSeparator, iterable, maxsplit=-1, yieldEmpty=False):
-    """Splits an iterator based on a predicate isSeparator."""
+    """itersplit(isSeparator, iterable, maxsplit=-1, yieldEmpty=False)
+
+    Splits an iterator based on a predicate isSeparator."""
     acc = []
     for element in iterable:
         if maxsplit == 0 or not isSeparator(element):