diff --git a/src/python/loxi/of14/instruction.py b/src/python/loxi/of14/instruction.py
index 5b451fa..cb457cc 100644
--- a/src/python/loxi/of14/instruction.py
+++ b/src/python/loxi/of14/instruction.py
@@ -60,7 +60,7 @@
         obj.type = reader.read("!H")[0]
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         return obj
 
     def __eq__(self, other):
@@ -104,7 +104,7 @@
         assert(_type == 4)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         reader.skip(4)
         obj.actions = loxi.generic_util.unpack_list(reader, action.action.unpack)
         return obj
@@ -164,7 +164,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         obj.experimenter = reader.read("!L")[0]
         obj.data = str(reader.read_all())
         return obj
@@ -223,7 +223,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         obj.subtype = reader.read("!L")[0]
@@ -271,7 +271,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -319,7 +319,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -367,7 +367,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -415,7 +415,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -463,7 +463,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -511,7 +511,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -559,7 +559,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -607,7 +607,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -655,7 +655,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -703,7 +703,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -751,7 +751,7 @@
         assert(_type == 65535)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         _experimenter = reader.read("!L")[0]
         assert(_experimenter == 6035143)
         _subtype = reader.read("!L")[0]
@@ -795,7 +795,7 @@
         assert(_type == 5)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         reader.skip(4)
         return obj
 
@@ -840,7 +840,7 @@
         assert(_type == 1)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         obj.table_id = reader.read("!B")[0]
         reader.skip(3)
         return obj
@@ -888,7 +888,7 @@
         assert(_type == 6)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         obj.meter_id = reader.read("!L")[0]
         return obj
 
@@ -936,7 +936,7 @@
         assert(_type == 3)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         reader.skip(4)
         obj.actions = loxi.generic_util.unpack_list(reader, action.action.unpack)
         return obj
@@ -990,7 +990,7 @@
         assert(_type == 2)
         _len = reader.read("!H")[0]
         orig_reader = reader
-        reader = orig_reader.slice(_len - (2 + 2))
+        reader = orig_reader.slice(_len, 4)
         reader.skip(4)
         obj.metadata = reader.read("!Q")[0]
         obj.metadata_mask = reader.read("!Q")[0]