diff --git a/jode/jode/bytecode/BytecodeInfo.java.in b/jode/jode/bytecode/BytecodeInfo.java.in
index 5c9fbf3..1148da1 100644
--- a/jode/jode/bytecode/BytecodeInfo.java.in
+++ b/jode/jode/bytecode/BytecodeInfo.java.in
@@ -64,7 +64,9 @@ public class BytecodeInfo extends BinaryInfo implements Opcodes {
 	int instructionCount = 0;
 
 	InstructionList() {
-	    borderInstr = new Instruction(opc_xxxunusedxxx);
+	    // opc_impdep1 is used as border instruction, it may not
+	    // occur in bytecode.
+	    borderInstr = new Instruction(opc_impdep1);
 	    borderInstr.nextByAddr = borderInstr.prevByAddr = borderInstr;
 	}
 
diff --git a/jode/jode/bytecode/Instruction.java b/jode/jode/bytecode/Instruction.java
index 1508962..48fc1e1 100644
--- a/jode/jode/bytecode/Instruction.java
+++ b/jode/jode/bytecode/Instruction.java
@@ -333,13 +333,13 @@ public final class Instruction implements Opcodes{
     }
 
     public final Instruction getPrevByAddr() {
-	if (prevByAddr.opcode == opc_xxxunusedxxx)
+	if (prevByAddr.opcode == opc_impdep1)
 	    return null;
 	return prevByAddr;
     }
 
     public final Instruction getNextByAddr() {
-	if (nextByAddr.opcode == opc_xxxunusedxxx)
+	if (nextByAddr.opcode == opc_impdep1)
 	    return null;
 	return nextByAddr;
     }
@@ -608,7 +608,7 @@ public final class Instruction implements Opcodes{
 	if (lnt != null) {
 	    for (int i=0; i< lnt.length; i++) {
 		if (lnt[i].start == this) {
-		    if (nextByAddr.opcode == opc_xxxunusedxxx
+		    if (nextByAddr.opcode == opc_impdep1
 			|| (i+1 < lnt.length 
 			    && lnt[i+1].start == nextByAddr)) {
 			/* Remove the line number.
diff --git a/jode/jode/bytecode/Opcodes.java b/jode/jode/bytecode/Opcodes.java
index e6edc8b..0234647 100644
--- a/jode/jode/bytecode/Opcodes.java
+++ b/jode/jode/bytecode/Opcodes.java
@@ -226,6 +226,8 @@ public interface Opcodes {
     public final static int opc_goto_w = 200;
     public final static int opc_jsr_w = 201;
     public final static int opc_breakpoint = 202;
+    public final static int opc_impdep1 = 254;
+    public final static int opc_impdep2 = 255;
 
     public final static String[] opcodeString = {
 	"nop", "aconst_null", "iconst_m1", "iconst_0", "iconst_1",