diff --git a/prism/src/explicit/ProductState.java b/prism/src/explicit/ProductState.java
index 1b35f764..fa0b8091 100644
--- a/prism/src/explicit/ProductState.java
+++ b/prism/src/explicit/ProductState.java
@@ -68,9 +68,9 @@ public class ProductState implements Comparable<ProductState>
 	@Override
 	public int compareTo(ProductState other)
 	{
-		int rv = Integer.compare(state_1, state_2);
+		int rv = Integer.compare(state_1, other.state_1);
 		if (rv == 0) {
-			return Integer.compare(state_1, state_2);
+			return Integer.compare(state_2, other.state_2);
 		} else {
 			return rv;
 		}