diff --git a/cpu.cpp b/cpu.cpp
index bbf2b81..fea4f90 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -1230,7 +1230,7 @@ bool cpu::single_operand_instructions(const uint16_t instr)
 							 v |= vl & 0xff00;
 
 						 setPSW_n(SIGN(v, word_mode));
-						 setPSW_z(IS_0(v, wm_word));
+						 setPSW_z(IS_0(v, word_mode));
 						 setPSW_c(SIGN(vl, word_mode));
 						 setPSW_v(getPSW_n() ^ getPSW_c());
 
@@ -1245,7 +1245,7 @@ bool cpu::single_operand_instructions(const uint16_t instr)
 
 						 if (set_flags) {
 							 setPSW_n(SIGN(v, word_mode));
-							 setPSW_z(IS_0(v, wm_word));
+							 setPSW_z(IS_0(v, word_mode));
 							 setPSW_c(SIGN(vl, word_mode));
 							 setPSW_v(getPSW_n() ^ getPSW_c());
 						 }