diff --git a/pac_encoder.hh b/pac_encoder.hh
index a9b0594..605c082 100644
--- a/pac_encoder.hh
+++ b/pac_encoder.hh
@@ -20,10 +20,12 @@ class PACEncoder
 	}
 	static bool conv(int *state, bool input)
 	{
-		bool s1 = *state & 1;
-		bool s2 = *state & 2;
-		bool output = input ^ s1 ^ s2;
-		*state = (s1 << 1) | output;
+		bool b1 = (*state >> 1) & 1;
+		bool b3 = (*state >> 3) & 1;
+		bool b4 = (*state >> 4) & 1;
+		bool b6 = (*state >> 6) & 1;
+		bool output = input ^ b1 ^ b3 ^ b4 ^ b6;
+		*state = ((*state & 126) << 1) | (input ? 2 : 0) | (output ? 1 : 0);
 		return output;
 	}
 public:
diff --git a/pac_list_decoder.hh b/pac_list_decoder.hh
index 3630120..0b0e130 100644
--- a/pac_list_decoder.hh
+++ b/pac_list_decoder.hh
@@ -41,10 +41,12 @@ struct PACListNode<TYPE, 0>
 	typedef typename PH::MAP MAP;
 	static bool conv(int *state, bool input)
 	{
-		bool s1 = *state & 1;
-		bool s2 = *state & 2;
-		bool output = input ^ s1 ^ s2;
-		*state = (s1 << 1) | output;
+		bool b1 = (*state >> 1) & 1;
+		bool b3 = (*state >> 3) & 1;
+		bool b4 = (*state >> 4) & 1;
+		bool b6 = (*state >> 6) & 1;
+		bool output = input ^ b1 ^ b3 ^ b4 ^ b6;
+		*state = ((*state & 126) << 1) | (input ? 2 : 0) | (output ? 1 : 0);
 		return output;
 	}
 	static MAP rate0(PATH *metric, TYPE *hard, TYPE *soft)