1 files changed, 3 insertions, 1 deletions

diff --git a/src/uk/ac/ox/cs/pagoda/rules/UpperProgram.java b/src/uk/ac/ox/cs/pagoda/rules/UpperProgram.java
index 46f22e3..52d60b7 100644
--- a/src/uk/ac/ox/cs/pagoda/rules/UpperProgram.java
+++ b/src/uk/ac/ox/cs/pagoda/rules/UpperProgram.java
@@ -1,10 +1,12 @@
 package uk.ac.ox.cs.pagoda.rules;
 
+import org.apache.commons.io.FilenameUtils;
+
 public abstract class UpperProgram extends ApproxProgram {
 
         @Override
         public String getOutputPath() {
-                return getDirectory() + "upper.dlog";
+                return FilenameUtils.concat(getDirectory(), "upper.dlog");
         }
 
 }