diff --git a/src/main/java/org/metacsp/multi/symbols/SymbolicValueConstraint.java b/src/main/java/org/metacsp/multi/symbols/SymbolicValueConstraint.java
index <HASH>..<HASH> 100644
--- a/src/main/java/org/metacsp/multi/symbols/SymbolicValueConstraint.java
+++ b/src/main/java/org/metacsp/multi/symbols/SymbolicValueConstraint.java
@@ -197,6 +197,8 @@ public class SymbolicValueConstraint extends MultiConstraint {
 

 	@Override

 	protected Constraint[] createInternalConstraints(Variable[] variables) {

+		if (variables == null || variables.length == 0) return null;

+		for (Variable var : variables) if (!(var instanceof SymbolicVariable)) return null;

 		Vector<Constraint> cons = new Vector<Constraint>();

 		if (this.type.equals(Type.EQUALS) || this.type.equals(Type.DIFFERENT)) {

 			for (int i = 0; i < variables.length; i++) {
Refactored SymbolicValueConstraints did not work with MultiVariables using SymbolicVariables - now fixed. --F.