diff --git a/src/FluxDecoder.cpp b/src/FluxDecoder.cpp
index 051ab01..6f0b92f 100644
--- a/src/FluxDecoder.cpp
+++ b/src/FluxDecoder.cpp
@@ -13,7 +13,6 @@ FluxDecoder::FluxDecoder (const FluxData &flux_revs, int bitcell_ns, int flux_sc
 	m_pll_adjust(pll_adjust)
 {
 	assert(flux_revs.size());
-	assert(flux_revs[0].size());
 
 	m_rev_it = m_flux_revs.cbegin();
 	m_flux_it = (*m_rev_it).cbegin();
@@ -111,6 +110,8 @@ int FluxDecoder::next_flux ()
 
 		m_index = true;
 		m_flux_it = (*m_rev_it).cbegin();
+		if (m_flux_it == (*m_rev_it).cend())
+			return -1;
 	}
 
 	auto time_ns = *m_flux_it++;
diff --git a/src/Sector.cpp b/src/Sector.cpp
index a46c15b..8ed2534 100644
--- a/src/Sector.cpp
+++ b/src/Sector.cpp
@@ -82,7 +82,7 @@ Sector::Merge Sector::add (Data &&new_data, bool bad_crc, uint8_t new_dam)
 		CRC16 crc;
 		if (encoding == Encoding::MFM) crc.init(CRC16::A1A1A1);
 		crc.add(new_dam);
-		auto bad_data_crc = crc.add(new_data.new_data(), size() + 2) != 0;
+		auto bad_data_crc = crc.add(new_data.data(), size() + 2) != 0;
 		assert(bad_crc == bad_data_crc);
 	}
 #endif