diff --git a/Storage/Disk/DiskImage/Formats/AppleDSK.cpp b/Storage/Disk/DiskImage/Formats/AppleDSK.cpp
index 699da7ecc..0d4a2fa5e 100644
--- a/Storage/Disk/DiskImage/Formats/AppleDSK.cpp
+++ b/Storage/Disk/DiskImage/Formats/AppleDSK.cpp
@@ -100,8 +100,8 @@ void AppleDSK::set_tracks(const std::map<Track::Address, std::shared_ptr<Track>>
 	std::map<Track::Address, std::vector<uint8_t>> tracks_by_address;
 	for(const auto &pair: tracks) {
 		// Decode the track.
-		const auto sector_map = Storage::Encodings::AppleGCR::sectors_from_segment(
-			Storage::Disk::track_serialisation(*pair.second, Storage::Time(1, 50000)));
+		const auto serialistion = Storage::Disk::track_serialisation(*pair.second, Storage::Time(1, 50000));
+		const auto sector_map = Storage::Encodings::AppleGCR::sectors_from_segment(serialistion);
 
 		// Rearrange sectors into Apple DOS or Pro-DOS order.
 		std::vector<uint8_t> track_contents(size_t(bytes_per_sector * sectors_per_track_));
diff --git a/Storage/Disk/Encodings/AppleGCR/Encoder.cpp b/Storage/Disk/Encodings/AppleGCR/Encoder.cpp
index fc9308d3b..0fa51e366 100644
--- a/Storage/Disk/Encodings/AppleGCR/Encoder.cpp
+++ b/Storage/Disk/Encodings/AppleGCR/Encoder.cpp
@@ -141,7 +141,7 @@ Storage::Disk::PCMSegment AppleGCR::AppleII::six_and_two_data(const uint8_t *sou
 	// and combined copies of the bottom two bits of the sector
 	// contents; the 256 bytes afterwards are the remaining
 	// six bits.
-	const uint8_t bit_reverse[] = {0, 2, 1, 3};
+	constexpr uint8_t bit_reverse[] = {0, 2, 1, 3};
 	for(std::size_t c = 0; c < 84; ++c) {
 		data[3 + c] =
 			uint8_t(
diff --git a/Storage/Disk/Encodings/AppleGCR/SegmentParser.cpp b/Storage/Disk/Encodings/AppleGCR/SegmentParser.cpp
index d68be8d7e..8df9d09ca 100644
--- a/Storage/Disk/Encodings/AppleGCR/SegmentParser.cpp
+++ b/Storage/Disk/Encodings/AppleGCR/SegmentParser.cpp
@@ -175,11 +175,12 @@ std::unique_ptr<Sector> decode_appleii_sector(const std::array<uint_fast8_t, 8>
 		}
 	}
 
-	// Undo the XOR step on sector contents and check that checksum.
+	// Undo the XOR step on sector contents, then check and discard the checksum.
 	for(std::size_t c = 1; c < sector->data.size(); ++c) {
 		sector->data[c] ^= sector->data[c-1];
 	}
 	if(sector->data.back()) return nullptr;
+	sector->data.resize(sector->data.size() - 1);
 
 	if(is_five_and_three) {
 		// TODO: the below is almost certainly incorrect; Beneath Apple DOS partly documents
@@ -275,7 +276,8 @@ std::map<std::size_t, Sector> Storage::Encodings::AppleGCR::sectors_from_segment
 					scanner[2] == five_and_three_header_prologue[2] ||
 					scanner[2] == header_prologue[2] ||
 					scanner[2] == data_prologue[2]
-				)) {
+				)
+			) {
 				pointer = 0;
 
 				if(scanner[2] != data_prologue[2]) {
@@ -309,20 +311,21 @@ std::map<std::size_t, Sector> Storage::Encodings::AppleGCR::sectors_from_segment
 					new_sector.reset();
 					pointer = scanning_sentinel;
 
+					const bool had_header = has_header;
+					has_header = false;
+
 					// Potentially this is a Macintosh sector.
-					auto macintosh_sector = decode_macintosh_sector(has_header ? &header : nullptr, sector);
+					auto macintosh_sector = decode_macintosh_sector(had_header ? &header : nullptr, sector);
 					if(macintosh_sector) {
 						result.insert(std::make_pair(sector_location, std::move(*macintosh_sector)));
 						continue;
 					}
 
 					// Apple II then?
-					auto appleii_sector = decode_appleii_sector(has_header ? &header : nullptr, sector, is_five_and_three);
+					auto appleii_sector = decode_appleii_sector(had_header ? &header : nullptr, sector, is_five_and_three);
 					if(appleii_sector) {
 						result.insert(std::make_pair(sector_location, std::move(*appleii_sector)));
 					}
-
-					has_header = false;
 				} else {
 					new_sector->data.push_back(value);
 				}