diff --git a/src/execute.c b/src/execute.c
index 55f69e6..8271719 100644
--- a/src/execute.c
+++ b/src/execute.c
@@ -80,7 +80,9 @@ static void writeRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regT
 
 // Updates N and Z condition codes given the machine and a result value
 static void updateCondNZ(Machine *state, dword result, a64inst_regType regType) {
-    state->conditionCodes.Negative = result & ((1 << (regType ? DWORD_BITS : WORD_BITS)) - 1);
+    size_t msb = (regType ? DWORD_BITS : WORD_BITS) - 1;
+
+    state->conditionCodes.Negative = result >> msb;
     state->conditionCodes.Zero = result == 0;
 }
 
@@ -243,7 +245,7 @@ void execute_SDT(Machine *state, a64inst_instruction *inst) {
         } else {
             state->registers[inst->data.SingleTransferData.target] = readDoubleWord(state->memory, address);
         }
-    }else {
+    } else {
         if (inst->data.SingleTransferData.regType == a64inst_W) {
             // 32 bit access
             state->registers[inst->data.SingleTransferData.target] = readWord(state->memory, address);