diff --git a/de.prob.ui/src/de/prob/ui/pragmas/InferredUnitPragmaAttribute.java b/de.prob.ui/src/de/prob/ui/pragmas/InferredUnitPragmaAttribute.java
index c72487a5b24ec7c54e4e60707cf9ff10f7eefcfd..6a7810049cac80b3c6807e5a979a4436d1205c9c 100644
--- a/de.prob.ui/src/de/prob/ui/pragmas/InferredUnitPragmaAttribute.java
+++ b/de.prob.ui/src/de/prob/ui/pragmas/InferredUnitPragmaAttribute.java
@@ -39,7 +39,7 @@ public class InferredUnitPragmaAttribute implements IAttributeManipulation {
 	@Override
 	public String[] getPossibleValues(IRodinElement element,
 			IProgressMonitor monitor) {
-		return new String[] { "", "a", "b", "c" };
+		return null;
 	}
 
 	@Override
diff --git a/de.prob.ui/src/de/prob/ui/pragmas/UnitPragmaAttribute.java b/de.prob.ui/src/de/prob/ui/pragmas/UnitPragmaAttribute.java
index b159c38b34a372231eb230b76f4a2a7aad4eed0e..74aa0f9a6a548f5cb754129a760d3561b9fc3d37 100644
--- a/de.prob.ui/src/de/prob/ui/pragmas/UnitPragmaAttribute.java
+++ b/de.prob.ui/src/de/prob/ui/pragmas/UnitPragmaAttribute.java
@@ -38,7 +38,7 @@ public class UnitPragmaAttribute implements IAttributeManipulation {
 	@Override
 	public String[] getPossibleValues(IRodinElement element,
 			IProgressMonitor monitor) {
-		return new String[] { "", "a", "b", "c" };
+		return null;
 	}
 
 	@Override