diff --git a/pac_encoder.hh b/pac_encoder.hh
index 1c6ce4e..6b642d1 100644
--- a/pac_encoder.hh
+++ b/pac_encoder.hh
@@ -26,7 +26,7 @@ class PACEncoder
 		return output;
 	}
 public:
-	void operator()(TYPE *codeword, const TYPE *message, const int *rank_map, int mesg_bits, int level)
+	void operator()(TYPE *codeword, const TYPE *message, const uint8_t *rank_map, int mesg_bits, int level)
 	{
 		int length = 1 << level;
 		int state = 0;
diff --git a/pac_list_decoder.hh b/pac_list_decoder.hh
index 74ec39e..ec8eb60 100644
--- a/pac_list_decoder.hh
+++ b/pac_list_decoder.hh
@@ -18,7 +18,7 @@ struct PACListTree
 	typedef typename PH::PATH PATH;
 	typedef typename PH::MAP MAP;
 	static const int N = 1 << M;
-	static MAP decode(PATH *metric, TYPE *message, MAP *maps, int *count, int *state, TYPE *hard, TYPE *soft, const int *rank, int frozen)
+	static MAP decode(PATH *metric, TYPE *message, MAP *maps, int *count, int *state, TYPE *hard, TYPE *soft, const uint8_t *rank, int frozen)
 	{
 		for (int i = 0; i < N/2; ++i)
 			soft[i+N/2] = PH::prod(soft[i+N], soft[i+N/2+N]);
@@ -97,7 +97,7 @@ struct PACListTree<TYPE, 1>
 		*hard = hrd;
 		return map;
 	}
-	static MAP decode(PATH *metric, TYPE *message, MAP *maps, int *count, int *state, TYPE *hard, TYPE *soft, const int *rank, int frozen)
+	static MAP decode(PATH *metric, TYPE *message, MAP *maps, int *count, int *state, TYPE *hard, TYPE *soft, const uint8_t *rank, int frozen)
 	{
 		soft[1] = PH::prod(soft[2], soft[3]);
 		MAP lmap, rmap;
@@ -118,7 +118,7 @@ struct PACListTree<TYPE, 1>
 template <typename TYPE, int MAX_M>
 class PACListDecoder
 {
-	static_assert(MAX_M >= 5 && MAX_M <= 16);
+	static_assert(MAX_M >= 5 && MAX_M <= 8);
 	typedef PolarHelper<TYPE> PH;
 	typedef typename TYPE::value_type VALUE;
 	typedef typename PH::PATH PATH;
@@ -128,7 +128,7 @@ class PACListDecoder
 	TYPE hard[MAX_N];
 	MAP maps[MAX_N];
 public:
-	void operator()(int *rank, TYPE *message, const VALUE *codeword, const int *rank_map, int mesg_bits, int level)
+	void operator()(int *rank, TYPE *message, const VALUE *codeword, const uint8_t *rank_map, int mesg_bits, int level)
 	{
 		assert(level <= MAX_M);
 		PATH metric[TYPE::SIZE];
@@ -149,14 +149,6 @@ public:
 		case 6: PACListTree<TYPE, 6>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
 		case 7: PACListTree<TYPE, 7>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
 		case 8: PACListTree<TYPE, 8>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 9: PACListTree<TYPE, 9>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 10: PACListTree<TYPE, 10>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 11: PACListTree<TYPE, 11>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 12: PACListTree<TYPE, 12>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 13: PACListTree<TYPE, 13>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 14: PACListTree<TYPE, 14>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 15: PACListTree<TYPE, 15>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
-		case 16: PACListTree<TYPE, 16>::decode(metric, message, maps, &count, state, hard, soft, rank_map, frozen); break;
 		default: assert(false);
 		}
 
diff --git a/tests/pac_list_regression_test.cc b/tests/pac_list_regression_test.cc
index 113e923..3985fa7 100644
--- a/tests/pac_list_regression_test.cc
+++ b/tests/pac_list_regression_test.cc
@@ -20,7 +20,7 @@ Copyright 2025 Ahmet Inan <inan@aicodix.de>
 
 int main()
 {
-	const int MAX_M = 10;
+	const int MAX_M = 8;
 	const int MAX_N = 1 << MAX_M;
 	const int M = 7;
 	const int N = 1 << M;
@@ -52,7 +52,7 @@ int main()
 	auto rel_seq = new int[MAX_N];
 	(*construct)(rel_seq, MAX_M);
 	delete construct;
-	auto rank_map = new int[N];
+	auto rank_map = new uint8_t[N];
 	for (int i = 0, j = 0; i < MAX_N && j < N; ++i) {
 		int index = rel_seq[i];
 		if (index < N)