diff --git a/jode/jode/expr/Expression.java b/jode/jode/expr/Expression.java
index e50146e..4ef1854 100644
--- a/jode/jode/expr/Expression.java
+++ b/jode/jode/expr/Expression.java
@@ -99,7 +99,7 @@ public abstract class Expression {
      * not checked.
      * @param op The combineable operator.
      * @return if this expression contains a matching load.  */
-    public boolean containsConflictingLoad(CombineableOperator op) {
+    public boolean containsConflictingLoad(MatchableOperator op) {
         return op.matches(getOperator());
     }
 
diff --git a/jode/jode/expr/InvokeOperator.java b/jode/jode/expr/InvokeOperator.java
index 1c36506..8889b09 100644
--- a/jode/jode/expr/InvokeOperator.java
+++ b/jode/jode/expr/InvokeOperator.java
@@ -24,7 +24,7 @@ import jode.Type;
 import jode.bytecode.ClassInfo;
 
 public final class InvokeOperator extends Operator 
-    implements CombineableOperator {
+    implements MatchableOperator {
     CodeAnalyzer codeAnalyzer;
     boolean specialFlag;
     MethodType methodType;
@@ -55,13 +55,6 @@ public final class InvokeOperator extends Operator
 	return expr.containsConflictingLoad(this);
     }
 
-    /**
-     * Makes a non void expression out of this invoke instruction.
-     */
-    public void makeNonVoid() {
-	throw new jode.AssertError("already non void");
-    }
-
     /**
      * Checks if the value of the operator can be changed by this expression.
      */