diff --git a/migrations/13-addon-dates.sql b/migrations/13-addon-dates.sql
new file mode 100644
index 0000000000..e3297dd341
--- /dev/null
+++ b/migrations/13-addon-dates.sql
@@ -0,0 +1,8 @@
+-- Addon dates should not be zero.
+UPDATE addons
+    SET modified=created
+    WHERE modified = 0;
+
+UPDATE addons
+    SET last_updated=created
+    WHERE last_updated=0;