diff --git a/elftools/dwarf/dwarf_expr.py b/elftools/dwarf/dwarf_expr.py
index 6140d20..7e1f65f 100644
--- a/elftools/dwarf/dwarf_expr.py
+++ b/elftools/dwarf/dwarf_expr.py
@@ -98,19 +98,11 @@
         self._cur_opcode_name = None
         self._cur_args = []
 
-    def process_expr(self, loc_expr):
-        """ Process (visit) a DWARF expression. Currently two possible
-            types are supported for expr:
-
-            1. File-like stream object
-            2. List of byte values (the result of parsed DW_FORM_block*
-               attributes).
+    def process_expr(self, expr):
+        """ Process (visit) a DWARF expression. expr should be a list of
+            (integer) byte values.
         """
-        if hasattr(loc_expr, 'read') and hasattr(loc_expr, 'seek'):
-            # looks like a stream
-            self.stream = loc_expr
-        else:
-            self.stream = StringIO(bytelist2string(loc_expr))
+        self.stream = StringIO(bytelist2string(expr))
 
         while True:
             # Get the next opcode from the stream. If nothing is left in the
diff --git a/tests/test_dwarf_expr.py b/tests/test_dwarf_expr.py
index 4202633..67cfc48 100644
--- a/tests/test_dwarf_expr.py
+++ b/tests/test_dwarf_expr.py
@@ -50,11 +50,6 @@
         self.assertEqual(self.visitor.get_str(),
             'DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul; DW_OP_mod; DW_OP_mul')
 
-    def test_stream_input(self):
-        self.visitor.process_expr(StringIO('\x1b'))
-        self.assertEqual(self.visitor.get_str(),
-            'DW_OP_div')
-
 
 if __name__ == '__main__':
     unittest.main()