diff --git a/Storage/Disk/Encodings/MFM/Shifter.cpp b/Storage/Disk/Encodings/MFM/Shifter.cpp
index 2c4437e3b..c0dc25803 100644
--- a/Storage/Disk/Encodings/MFM/Shifter.cpp
+++ b/Storage/Disk/Encodings/MFM/Shifter.cpp
@@ -24,7 +24,7 @@ void Shifter::set_should_obey_syncs(bool should_obey_syncs) {
 }
 
 void Shifter::add_input_bit(int value) {
-	shift_register_ = (shift_register_ << 1) | value;
+	shift_register_ = (shift_register_ << 1) | static_cast<unsigned int>(value);
 	bits_since_token_++;
 
 	token_ = Token::None;
diff --git a/Storage/Disk/Encodings/MFM/Shifter.hpp b/Storage/Disk/Encodings/MFM/Shifter.hpp
index 54b315b3e..5ceca2edd 100644
--- a/Storage/Disk/Encodings/MFM/Shifter.hpp
+++ b/Storage/Disk/Encodings/MFM/Shifter.hpp
@@ -40,10 +40,10 @@ class Shifter {
 	private:
 		// Bit stream input state
 		int bits_since_token_ = 0;
-		int shift_register_ = 0;
+		unsigned int shift_register_ = 0;
 		bool is_awaiting_marker_value_ = false;
-		bool should_obey_syncs_;
-		Token token_;
+		bool should_obey_syncs_ = true;
+		Token token_ = None;
 
 		// input configuration
 		bool is_double_density_ = false;