diff --git a/ethereumj-core/src/main/java/org/ethereum/jsontestsuite/TestRunner.java b/ethereumj-core/src/main/java/org/ethereum/jsontestsuite/TestRunner.java
index ac538d96..11f0066f 100644
--- a/ethereumj-core/src/main/java/org/ethereum/jsontestsuite/TestRunner.java
+++ b/ethereumj-core/src/main/java/org/ethereum/jsontestsuite/TestRunner.java
@@ -298,7 +298,7 @@ public class TestRunner {
         if (!expectedGas.equals(actualGas)) {
 
             String output =
-                    String.format("Gas usage is different. Expected gas usage: [ %s ], actual gas usage: [ %s ]",
+                    String.format("Gas remaining is different. Expected gas remaining: [ %s ], actual gas remaining: [ %s ]",
                             expectedGas.toString() ,
                             actualGas.toString());
             logger.info(output);
diff --git a/ethereumj-core/src/main/java/org/ethereum/vm/Program.java b/ethereumj-core/src/main/java/org/ethereum/vm/Program.java
index 0d689815..d48a0cbf 100644
--- a/ethereumj-core/src/main/java/org/ethereum/vm/Program.java
+++ b/ethereumj-core/src/main/java/org/ethereum/vm/Program.java
@@ -751,6 +751,9 @@ public class Program {
 	public class OutOfGasException extends RuntimeException {
 	}
 	
+    @SuppressWarnings("serial")
+    public class IllegalOperationException extends RuntimeException {}
+	
 	@SuppressWarnings("serial")
 	public class StackTooSmallException extends RuntimeException {
 		public StackTooSmallException(String message) {
diff --git a/ethereumj-core/src/main/java/org/ethereum/vm/VM.java b/ethereumj-core/src/main/java/org/ethereum/vm/VM.java
index 5935121e..769b30c7 100644
--- a/ethereumj-core/src/main/java/org/ethereum/vm/VM.java
+++ b/ethereumj-core/src/main/java/org/ethereum/vm/VM.java
@@ -80,7 +80,7 @@ public class VM {
             OpCode op = OpCode.code(program.getCurrentOp());
             
             if (op == null)
-            	throw new IllegalOperationException();
+            	throw program.new IllegalOperationException();
             
             program.setLastOp(op.val());
 
@@ -1080,7 +1080,4 @@ public class VM {
 					gasBefore, gasCost, memWords);    	
     	}
     }
-    
-    @SuppressWarnings("serial")
-    public class IllegalOperationException extends RuntimeException {}
 }
\ No newline at end of file
diff --git a/ethereumj-core/src/test/java/org/ethereum/vm/VMTest.java b/ethereumj-core/src/test/java/org/ethereum/vm/VMTest.java
index 4ffbb404..556a8635 100644
--- a/ethereumj-core/src/test/java/org/ethereum/vm/VMTest.java
+++ b/ethereumj-core/src/test/java/org/ethereum/vm/VMTest.java
@@ -5,7 +5,6 @@ import org.ethereum.util.ByteUtil;
 import org.ethereum.vm.Program.OutOfGasException;
 import org.ethereum.vm.Program.PcOverflowException;
 import org.ethereum.vm.Program.StackTooSmallException;
-import org.ethereum.vm.VM.IllegalOperationException;
 import org.junit.FixMethodOrder;
 import org.junit.Test;
 import org.junit.runners.MethodSorters;
@@ -3336,7 +3335,7 @@ public class VMTest {
         assertEquals(s_expected_1, Hex.toHexString(item1.getData()).toUpperCase());
     }
     
-    @Test(expected=IllegalOperationException.class) // INVALID OP
+    @Test(expected=Program.IllegalOperationException.class) // INVALID OP
     public void testINVALID_1() {
 
         VM vm = new VM();