diff --git a/changelog/snippets/fix.6609.md b/changelog/snippets/fix.6609.md
new file mode 100644
index 0000000000..e15719897a
--- /dev/null
+++ b/changelog/snippets/fix.6609.md
@@ -0,0 +1 @@
+- (#6609) Fix drones meant to rebuild unbuilt units during unit transfer not being cleaned up when rebuilding fails.
diff --git a/lua/SimUtils.lua b/lua/SimUtils.lua
index 3e0ce062e6..d1c9303a34 100644
--- a/lua/SimUtils.lua
+++ b/lua/SimUtils.lua
@@ -533,7 +533,7 @@ end
 ---@param army Army
 function TryRebuildUnits(trackers, army)
     local rebuilders = {}
-    for k, tracker in ipairs(trackers) do
+    for k, tracker in trackers do
         if tracker.Success then
             continue
         end
@@ -555,7 +555,7 @@ function TryRebuildUnits(trackers, army)
 
     WaitTicks(1)
 
-    for k, rebuilder in ipairs(rebuilders) do
+    for k, rebuilder in rebuilders do
         local tracker = trackers[k]
         local newUnit = rebuilder:GetFocusUnit()
         local progressDif = rebuilder:GetWorkProgress() - tracker.UnitProgress