diff --git a/polar_parity_aided.hh b/polar_parity_aided.hh
index 4a7f31a..6149274 100644
--- a/polar_parity_aided.hh
+++ b/polar_parity_aided.hh
@@ -20,10 +20,10 @@ class PolarParityEncoder
 		return (bits[idx/32] >> (idx%32)) & 1;
 	}
 public:
-	void operator()(TYPE *codeword, const TYPE *message, const uint32_t *frozen, int level, int stride)
+	void operator()(TYPE *codeword, const TYPE *message, const uint32_t *frozen, int level, int stride, int first)
 	{
 		int length = 1 << level;
-		int count = stride;
+		int count = first;
 		TYPE parity = PH::one();
 		for (int i = 0; i < length; i += 2) {
 			TYPE msg0, msg1;
@@ -345,7 +345,7 @@ class PolarParityDecoder
 	TYPE hard[MAX_N];
 	MAP maps[MAX_N];
 public:
-	void operator()(PATH *metric, TYPE *message, const VALUE *codeword, const uint32_t *frozen, int level, int stride)
+	void operator()(PATH *metric, TYPE *message, const VALUE *codeword, const uint32_t *frozen, int level, int stride, int first)
 	{
 		assert(level <= MAX_M);
 		int index = 0;
@@ -356,7 +356,7 @@ public:
 		for (int i = 0; i < length; ++i)
 			soft[length+i] = vdup<TYPE>(codeword[i]);
 		TYPE parity = PH::one();
-		int count = stride;
+		int count = first;
 
 		switch (level) {
 		case 5: PolarParityTree<TYPE, 5>::decode(metric, message, maps, &index, hard, soft, *frozen, &parity, &count, stride); break;
diff --git a/tests/polar_list_regression_test.cc b/tests/polar_list_regression_test.cc
index 5cf2cff..3bfb4f3 100644
--- a/tests/polar_list_regression_test.cc
+++ b/tests/polar_list_regression_test.cc
@@ -84,6 +84,9 @@ int main()
 	for (int i = 0; i < N - K; ++i)
 		frozen[reliability_sequence[i]/32] |= 1 << (reliability_sequence[i]%32);
 	int P = K / (S + 1);
+	int F = K % (S + 1);
+	if (!crc_aided)
+		F += S;
 	if (par_aided)
 		K -= P;
 	std::cerr << "Polar(" << N << ", " << K << ")" << std::endl;
@@ -142,7 +145,7 @@ int main()
 						assert(codeword[i] == message[j++]);
 			} else if (par_aided) {
 				CODE::PolarParityEncoder<code_type> encode;
-				encode(codeword, message, frozen, M, S);
+				encode(codeword, message, frozen, M, S, F);
 			} else {
 				CODE::PolarEncoder<code_type> encode;
 				encode(codeword, message, frozen, M);
@@ -169,7 +172,7 @@ int main()
 
 			auto start = std::chrono::system_clock::now();
 			if (par_aided)
-				(*par_dec)(metric, decoded, codeword, frozen, M, S);
+				(*par_dec)(metric, decoded, codeword, frozen, M, S, F);
 			else
 				(*decode)(metric, decoded, codeword, frozen, M);
 			auto end = std::chrono::system_clock::now();