diff --git a/src/sim65/6502.c b/src/sim65/6502.c
index ff24c02e0..bfb3f3e9b 100644
--- a/src/sim65/6502.c
+++ b/src/sim65/6502.c
@@ -664,15 +664,12 @@ static unsigned HaveIRQRequest;
 
 
 /* ADC, binary mode (6502 and 65C02) */
-/* TODO: once the Regs fields are properly sized, get rid of the
- * "& 0xff" in the Regs.AC asignment.
- */
 #define ADC_BINARY_MODE(v)                                      \
     do {                                                        \
         const uint8_t op = v;                                   \
         const uint8_t OldAC = Regs.AC;                          \
         bool carry = GET_CF();                                  \
-        Regs.AC = (OldAC + op + carry) & 0xff;                  \
+        Regs.AC = (OldAC + op + carry);                         \
         const bool NV = Regs.AC >= 0x80;                        \
         carry = OldAC + op + carry >= 0x100;                    \
         SET_SF(NV);                                             \
@@ -1033,15 +1030,12 @@ static unsigned HaveIRQRequest;
     TEST_ZF (Val)
 
 /* SBC, binary mode (6502 and 65C02) */
-/* TODO: once the Regs fields are properly sized, get rid of the
- * "& 0xff" in the Regs.AC asignment.
- */
 #define SBC_BINARY_MODE(v)                                      \
     do {                                                        \
         const uint8_t op = v;                                   \
         const uint8_t OldAC = Regs.AC;                          \
         const bool borrow = !GET_CF();                          \
-        Regs.AC = (OldAC - op - borrow) & 0xff;                 \
+        Regs.AC = (OldAC - op - borrow);                        \
         const bool NV = Regs.AC >= 0x80;                        \
         SET_SF(NV);                                             \
         SET_OF(((OldAC >= 0x80) ^ NV) & ((op < 0x80) ^ NV));    \
diff --git a/src/sim65/6502.h b/src/sim65/6502.h
index b6b621823..0f4d066d0 100644
--- a/src/sim65/6502.h
+++ b/src/sim65/6502.h
@@ -37,6 +37,8 @@
 #define _6502_H
 
 
+#include <stdint.h>
+
 
 /*****************************************************************************/
 /*                                   Data                                    */
@@ -57,12 +59,12 @@ extern CPUType CPU;
 /* 6502 CPU registers */
 typedef struct CPURegs CPURegs;
 struct CPURegs {
-    unsigned    AC;             /* Accumulator */
-    unsigned    XR;             /* X register */
-    unsigned    YR;             /* Y register */
-    unsigned    SR;             /* Status register */
-    unsigned    SP;             /* Stackpointer */
-    unsigned    PC;             /* Program counter */
+    uint8_t     AC;             /* Accumulator */
+    uint8_t     XR;             /* X register */
+    uint8_t     YR;             /* Y register */
+    uint8_t     SR;             /* Status register */
+    uint8_t     SP;             /* Stackpointer */
+    uint16_t    PC;             /* Program counter */
 };
 
 /* Current CPU registers */