diff --git a/de.prob.units/src/de/prob/units/sc/MachineAttributeProcessor.java b/de.prob.units/src/de/prob/units/sc/MachineAttributeProcessor.java
index 92a739fd10b4a132c66b917a0b0d74e16293b648..f2c750af58965c5f4e4a83781a58cdc75522796d 100644
--- a/de.prob.units/src/de/prob/units/sc/MachineAttributeProcessor.java
+++ b/de.prob.units/src/de/prob/units/sc/MachineAttributeProcessor.java
@@ -40,8 +40,8 @@ public class MachineAttributeProcessor extends SCProcessorModule {
 			return;
 
 		for (IVariable var : variables) {
-			ISCVariable scVar = scMachineRoot.getSCVariable(var
-					.getIdentifierString());
+			String identifier = var.getIdentifierString();
+			ISCVariable scVar = scMachineRoot.getSCVariable(identifier);
 
 			// might have been filtered out by previous modules
 			if (scVar.exists()) {