diff --git a/prism/src/parser/Values.java b/prism/src/parser/Values.java
index 96aa84bb..eb18807b 100644
--- a/prism/src/parser/Values.java
+++ b/prism/src/parser/Values.java
@@ -241,16 +241,19 @@ public class Values implements Cloneable //implements Comparable
 	public int getIntValue(int i) throws PrismLangException
 	{
 		Object o;
-		
+
 		o = values.get(i);
-		
+
 		if (o instanceof Boolean) {
 			return ((Boolean)o).booleanValue() ? 1 : 0;
 		}
 		if (o instanceof Integer) {
 			return ((Integer)o).intValue();
 		}
-		
+		if (o instanceof BigRational) {
+			return ((BigRational)o).toInt();
+		}
+
 		throw new PrismLangException("Cannot get integer value for \"" + getName(i) + "\"");
 	}
 
@@ -273,6 +276,9 @@ public class Values implements Cloneable //implements Comparable
 		if (o instanceof Double) {
 			return ((Double)o).doubleValue();
 		}
+		if (o instanceof BigRational) {
+			return ((BigRational)o).doubleValue();
+		}
 		
 		throw new PrismLangException("Cannot get double value for \"" + getName(i) + "\"");
 	}
@@ -283,14 +289,16 @@ public class Values implements Cloneable //implements Comparable
 	public boolean getBooleanValue(int i) throws PrismLangException
 	{
 		Object o;
-		
+
 		o = values.get(i);
-		
-		if (!(o instanceof Boolean)) {
+
+		if (o instanceof Boolean) {
+			return ((Boolean)o).booleanValue();
+		} else if (o instanceof BigRational) {
+			return ((BigRational)o).toBoolean();
+		} else {
 			throw new PrismLangException("Cannot get boolean value for \"" + getName(i) + "\"");
 		}
-		
-		return ((Boolean)o).booleanValue();
 	}
 
 	/**