diff --git a/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Db.kt b/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Db.kt
index 87ca446eb3..392fa6579a 100644
--- a/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Db.kt
+++ b/leakcanary-android-core/src/main/java/leakcanary/internal/activity/db/Db.kt
@@ -45,6 +45,7 @@ internal object Db {
     // Closing on the serial IO thread to ensure we don't close while using the db.
     Io.execute {
       dbHelper?.close()
+      dbHelper = null
     }
   }
 }