diff --git a/mutants/mutant-2/swen90006/machine/Machine.java b/mutants/mutant-2/swen90006/machine/Machine.java
index 9bf57316d1c736ea2bd1c62bd6df3c6c0282f331..e9ff6c7b9fff0d7fb24da5ac77c1c2f9a1c38347 100644
--- a/mutants/mutant-2/swen90006/machine/Machine.java
+++ b/mutants/mutant-2/swen90006/machine/Machine.java
@@ -1,4 +1,7 @@
 package swen90006.machine;
+/*
+* change all the pc+1 to pc-1
+*/
 
 import java.util.Arrays;
 import java.util.List;
@@ -188,7 +191,7 @@ public class Machine
 
       /* check for blank lines */
       if (inst.equals("")){
-	pc = pc + 1;
+	pc = pc - 1;
 	count++;
 	continue;
       }
@@ -278,7 +281,7 @@ public class Machine
 	if (regs[ra] == 0){
 	  pc = pc + offs;
 	}else{
-	  pc = pc + 1;
+	  pc = pc - 1;
 	}
 	count++;
 	continue; /* avoid default increment the pc below */
@@ -287,7 +290,7 @@ public class Machine
 	throw new InvalidInstructionException();
       }
       count++;
-      pc = pc + 1;
+      pc = pc - 1;
     }
 
     /* got here without returning already... */