diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
index 6ad88faae1..fe675273fb 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java
@@ -44,8 +44,8 @@ import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
-import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchLineComment.Status;
+import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchSet.Id;
 import com.google.gerrit.reviewdb.client.PatchSetApproval;
 import com.google.gerrit.reviewdb.client.PatchSetApproval.LabelId;
@@ -152,7 +152,7 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
     }
   }
 
-  private static class Parser {
+  private static class Parser implements AutoCloseable {
     private final Change.Id changeId;
     private final ObjectId tip;
     private final RevWalk walk;
@@ -184,6 +184,11 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       commentsForBase = ArrayListMultimap.create();
     }
 
+    @Override
+    public void close() {
+      repo.close();
+    }
+
     private void parseAll() throws ConfigInvalidException, IOException, ParseException {
       walk.markStart(walk.parseCommit(tip));
       for (RevCommit commit : walk) {
@@ -626,9 +631,7 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       return;
     }
     RevWalk walk = new RevWalk(reader);
-    try {
-      Change change = getChange();
-      Parser parser = new Parser(change, rev, walk, repoManager);
+    try (Parser parser = new Parser(change, rev, walk, repoManager)) {
       parser.parseAll();
 
       if (parser.status != null) {
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/DraftCommentNotes.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
index 918f9234e1..49542a7320 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
@@ -68,7 +68,7 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
     }
   }
 
-  private static class Parser {
+  private static class Parser implements AutoCloseable {
     private final Change.Id changeId;
     private final ObjectId tip;
     private final RevWalk walk;
@@ -92,6 +92,11 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
       draftPsComments = ArrayListMultimap.create();
     }
 
+    @Override
+    public void close() {
+      repo.close();
+    }
+
     private void parseDraftComments() throws IOException, ConfigInvalidException {
       walk.markStart(walk.parseCommit(tip));
       noteMap = CommentsInNotesUtil.parseCommentsFromNotes(repo,
@@ -167,13 +172,16 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
     }
 
     RevWalk walk = new RevWalk(reader);
-    Parser parser = new Parser(getChangeId(), walk, rev, repoManager,
-        draftsProject, author);
-    parser.parseDraftComments();
+    try (Parser parser = new Parser(getChangeId(), walk, rev, repoManager,
+        draftsProject, author)) {
+      parser.parseDraftComments();
 
-    buildCommentTable(draftBaseComments, parser.draftBaseComments);
-    buildCommentTable(draftPsComments, parser.draftPsComments);
-    noteMap = parser.noteMap;
+      buildCommentTable(draftBaseComments, parser.draftBaseComments);
+      buildCommentTable(draftPsComments, parser.draftPsComments);
+      noteMap = parser.noteMap;
+    } finally {
+      walk.release();
+    }
   }
 
   @Override