diff --git a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/engines/BlackboxGradingEngine.java b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/engines/BlackboxGradingEngine.java
index fd5ab4836..aa912aea4 100644
--- a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/engines/BlackboxGradingEngine.java
+++ b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/engines/BlackboxGradingEngine.java
@@ -49,7 +49,6 @@ public abstract class BlackboxGradingEngine implements GradingEngine {
     private File gradingDir;
     private File compilationDir;
     private File evaluationDir;
-    private File scoringDir;
 
     private GradingConfig config;
     private GradingLanguage language;
@@ -141,8 +140,6 @@ private void createGradingDirs() throws PreparationException {
             FileUtils.forceMkdir(compilationDir);
             evaluationDir = new File(gradingDir, "evaluation");
             FileUtils.forceMkdir(evaluationDir);
-            scoringDir = new File(gradingDir, "scoring");
-            FileUtils.forceMkdir(scoringDir);
         } catch (IOException e) {
             throw new PreparationException(e);
         }
diff --git a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/DiffScorer.java b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/DiffScorer.java
index 2068747d0..b73acc4a9 100644
--- a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/DiffScorer.java
+++ b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/DiffScorer.java
@@ -9,6 +9,12 @@
 import judgels.gabriel.api.Verdict;
 
 public class DiffScorer implements Scorer {
+    private final File evaluationDir;
+
+    public DiffScorer(File evaluationDir) {
+        this.evaluationDir = evaluationDir;
+    }
+
     @Override
     public ScoringResult score(File input, File output, File evaluationOutput) throws ScoringException {
         String[] scoringCommand = new String[]{"/bin/bash", "-c", String.format(""
@@ -16,11 +22,13 @@ public ScoringResult score(File input, File output, File evaluationOutput) throw
                 + "cat \"%s\" | tr '[\\t\\r\\n]' ' ' | xargs > _evaluation_tokenized.out; "
                 + "diff --brief _output_tokenized.out _evaluation_tokenized.out; result=$?; "
                 + "rm _output_tokenized.out _evaluation_tokenized.out; "
-                + "exit $result;",
+                + "exit $result",
                 output.getAbsolutePath(),
                 evaluationOutput.getAbsolutePath())};
 
         ProcessBuilder pb = new ProcessBuilder(scoringCommand);
+        pb.directory(evaluationDir);
+
         int exitCode;
         try {
             exitCode = pb.start().waitFor();
diff --git a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/ScorerRegistry.java b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/ScorerRegistry.java
index 092904f38..97e3da702 100644
--- a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/ScorerRegistry.java
+++ b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/helpers/scorer/ScorerRegistry.java
@@ -18,7 +18,7 @@ private ScorerRegistry() {}
     public static Scorer getAndPrepare(
             Optional<String> customScorer,
             Map<String, File> helperFiles,
-            @Nullable  Sandbox sandbox,
+            @Nullable Sandbox sandbox,
             File evaluationDir) throws PreparationException {
 
         if (customScorer.isPresent()) {
@@ -27,7 +27,7 @@ public static Scorer getAndPrepare(
             scorer.prepare(sandbox, evaluationDir, language, scorerFile);
             return scorer;
         } else {
-            return new DiffScorer();
+            return new DiffScorer(evaluationDir);
         }
     }
 }