diff --git a/src/devices/cpu/ks0164/ks0164.cpp b/src/devices/cpu/ks0164/ks0164.cpp
index f4122eeab5d..0c337a2bf11 100644
--- a/src/devices/cpu/ks0164/ks0164.cpp
+++ b/src/devices/cpu/ks0164/ks0164.cpp
@@ -577,7 +577,7 @@ void ks0164_cpu_device::execute_run()
 				m_r[R_PC] += 2;
 
 				m_r[r] --;
-				if(m_r[r] != 0xffff)
+				if(m_r[r] != 0)
 					m_r[R_PC] = a;
 				break;
 			}