diff --git a/eos/db/migrations/upgrade21.py b/eos/db/migrations/upgrade21.py
new file mode 100644
index 000000000..8545f5ecf
--- /dev/null
+++ b/eos/db/migrations/upgrade21.py
@@ -0,0 +1,9 @@
+"""
+Migration 21
+
+- Fixes discrepancy in drone table where we may have an amount active that is not equal to the amount in the stack
+  (we don't support activating only 2/5 drones). See GH issue #728
+"""
+
+def upgrade(saveddata_engine):
+    saveddata_engine.execute("UPDATE drones SET amountActive = amount where amountActive > 0 AND amountActive <> amount;")