diff --git a/src/mos6502.bits.c b/src/mos6502.bits.c
index 66bb4ab..f714bd5 100644
--- a/src/mos6502.bits.c
+++ b/src/mos6502.bits.c
@@ -54,7 +54,7 @@ DEFINE_INST(bit)
     // We're just relying on the modify_status function to do negative
     // and zero; we also need to do overflow, but overflow is checked in
     // a slightly different way with BIT...
-    mos6502_modify_status(cpu, MOS_NZ, oper, oper);
+    mos6502_modify_status(cpu, MOS_NZ, oper, cpu->A & oper);
 
     // Normally, overflow is handled by checking if bit 7 flipped from 0
     // to 1 or vice versa, and that's done by comparing the result to