diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5fd60bb1..15a433ec2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 Change Log
 ---
-### 6.9 (unreleased)
+### 6.9 (2019-09-23)
 
 * Synchronize tags with CalDAV
 * Target Android 10
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 349a282d8..a19d802a0 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -34,7 +34,7 @@ android {
     defaultConfig {
         testApplicationId = "org.tasks.test"
         applicationId = "org.tasks"
-        versionCode = 612
+        versionCode = 613
         versionName = "6.9"
         targetSdkVersion(Versions.targetSdk)
         minSdkVersion(Versions.minSdk)
diff --git a/app/src/main/java/com/todoroo/astrid/dao/TaskDao.java b/app/src/main/java/com/todoroo/astrid/dao/TaskDao.java
index c2136b4fb..12fa8cdef 100644
--- a/app/src/main/java/com/todoroo/astrid/dao/TaskDao.java
+++ b/app/src/main/java/com/todoroo/astrid/dao/TaskDao.java
@@ -86,7 +86,7 @@ public abstract class TaskDao {
 
   @Query(
       "SELECT * FROM tasks WHERE remoteId IN (:remoteIds) "
-          + "AND recurrence NOT NULL AND LENGTH(recurrence) > 0")
+          + "AND recurrence IS NOT NULL AND LENGTH(recurrence) > 0")
   public abstract List<Task> getRecurringTasks(List<String> remoteIds);
 
   @Query("UPDATE tasks SET completed = :completionDate " + "WHERE remoteId = :remoteId")
@@ -120,20 +120,20 @@ public abstract class TaskDao {
   @Query("SELECT * FROM tasks")
   public abstract List<Task> getAll();
 
-  @Query("SELECT calendarUri FROM tasks " + "WHERE calendarUri NOT NULL AND calendarUri != ''")
+  @Query("SELECT calendarUri FROM tasks " + "WHERE calendarUri IS NOT NULL AND calendarUri != ''")
   public abstract List<String> getAllCalendarEvents();
 
-  @Query("UPDATE tasks SET calendarUri = '' " + "WHERE calendarUri NOT NULL AND calendarUri != ''")
+  @Query("UPDATE tasks SET calendarUri = '' " + "WHERE calendarUri IS NOT NULL AND calendarUri != ''")
   public abstract int clearAllCalendarEvents();
 
   @Query(
       "SELECT calendarUri FROM tasks "
-          + "WHERE completed > 0 AND calendarUri NOT NULL AND calendarUri != ''")
+          + "WHERE completed > 0 AND calendarUri IS NOT NULL AND calendarUri != ''")
   public abstract List<String> getCompletedCalendarEvents();
 
   @Query(
       "UPDATE tasks SET calendarUri = '' "
-          + "WHERE completed > 0 AND calendarUri NOT NULL AND calendarUri != ''")
+          + "WHERE completed > 0 AND calendarUri IS NOT NULL AND calendarUri != ''")
   public abstract int clearCompletedCalendarEvents();
 
   @RawQuery
diff --git a/app/src/main/java/org/tasks/data/CaldavDao.java b/app/src/main/java/org/tasks/data/CaldavDao.java
index 50cac47e0..4f06f526f 100644
--- a/app/src/main/java/org/tasks/data/CaldavDao.java
+++ b/app/src/main/java/org/tasks/data/CaldavDao.java
@@ -67,7 +67,7 @@ public interface CaldavDao {
   @Query(
       "SELECT task.*, caldav_task.* FROM tasks AS task "
           + "INNER JOIN caldav_tasks AS caldav_task ON _id = cd_task "
-          + "WHERE cd_deleted = 0 AND cd_vtodo NOT NULL AND cd_vtodo != ''")
+          + "WHERE cd_deleted = 0 AND cd_vtodo IS NOT NULL AND cd_vtodo != ''")
   List<CaldavTaskContainer> getTasks();
 
   @Query("SELECT * FROM caldav_lists ORDER BY cdl_name COLLATE NOCASE")