diff --git a/InstructionSets/M50740/Decoder.cpp b/InstructionSets/M50740/Decoder.cpp
index 2e526eb62..03be2f5e4 100644
--- a/InstructionSets/M50740/Decoder.cpp
+++ b/InstructionSets/M50740/Decoder.cpp
@@ -235,6 +235,12 @@ std::pair<int, InstructionSet::M50740::Instruction> Decoder::decode(const uint8_
 
 #undef Map
 		}
+
+		// TODO: can I build these into the AddressingMode constants, to avoid the switch?
+		switch(instr_.addressing_mode) {
+			default: operand_size_ = 0; break;
+		}
+
 	}
 
 	return std::make_pair(0, Instruction());
diff --git a/InstructionSets/M50740/Decoder.hpp b/InstructionSets/M50740/Decoder.hpp
index d7a08e3a4..68bdd3396 100644
--- a/InstructionSets/M50740/Decoder.hpp
+++ b/InstructionSets/M50740/Decoder.hpp
@@ -11,6 +11,7 @@
 
 #include "Instruction.hpp"
 
+#include <cstddef>
 #include <utility>
 
 namespace InstructionSet {
diff --git a/InstructionSets/x86/Decoder.hpp b/InstructionSets/x86/Decoder.hpp
index f09dd7fc0..084cac843 100644
--- a/InstructionSets/x86/Decoder.hpp
+++ b/InstructionSets/x86/Decoder.hpp
@@ -11,6 +11,7 @@
 
 #include "Instruction.hpp"
 
+#include <cstddef>
 #include <utility>
 
 namespace InstructionSet {