diff --git a/InstructionSets/ARM/OperationMapper.hpp b/InstructionSets/ARM/OperationMapper.hpp
index 9058f8df2..e60b07c40 100644
--- a/InstructionSets/ARM/OperationMapper.hpp
+++ b/InstructionSets/ARM/OperationMapper.hpp
@@ -142,7 +142,7 @@ struct DataProcessingFlags {
 
 	/// @returns The operation to apply.
 	constexpr DataProcessingOperation operation() const {
-		return DataProcessingOperation((flags_ >> 21) & 0xf);
+		return DataProcessingOperation((flags_ >> (21 - FlagsStartBit)) & 0xf);
 	}
 
 	/// @returns @c true if operand 2 is defined by the @c rotate() and @c immediate() fields;
@@ -232,7 +232,7 @@ struct SingleDataTransferFlags {
 		return flag_bit<20>(flags_) ? Operation::LDR : Operation::STR;
 	}
 
-	constexpr bool offset_is_immediate() const	{	return flag_bit<25>(flags_);	}
+	constexpr bool offset_is_immediate() const	{	return !flag_bit<25>(flags_);	}
 	constexpr bool pre_index() const			{	return flag_bit<24>(flags_);	}
 	constexpr bool add_offset() const			{	return flag_bit<23>(flags_);	}
 	constexpr bool transfer_byte() const		{	return flag_bit<22>(flags_);	}
diff --git a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm
index 05955cf18..004e7ac9e 100644
--- a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
@@ -203,7 +203,7 @@ struct Memory {
 	executor.bus_.rom = roms.find(rom_name)->second;
 
 	uint32_t pc = 0;
-	for(int c = 0; c < 100; c++) {
+	for(int c = 0; c < 200; c++) {
 		uint32_t instruction;
 		executor.bus_.read(pc, instruction, executor.mode(), false);