diff --git a/docs/changelog.txt b/docs/changelog.txt
index e078c870da..d5e9d33ec2 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -73,6 +73,7 @@ Template for new versions:
 - `buildingplan`: fix "Unlink all" only unlinking some mechanisms (or crashing) when freeing mechanisms from the building
 - `timestream`: deal properly with units who have breathing difficulties
 - `stocks`: overlay now resets scroll position when collapsing categories so the item list is no longer left blank and unscrollable
+- Fixed persistent site data API (``dfhack.persistent.saveSiteData``/``getSiteData``) failing on newly reclaimed fortresses until the first save
 
 ## Misc Improvements
 - Added ``Coord2d`` and ``Coord3d`` C++ templates, providing a standard set operations for 2-tuples and 3-tuples of any numeric type
diff --git a/library/modules/World.cpp b/library/modules/World.cpp
index c0c6d590fd..020e76127d 100644
--- a/library/modules/World.cpp
+++ b/library/modules/World.cpp
@@ -217,8 +217,15 @@ df::unit * World::getAdventurer() {
 int32_t World::GetCurrentSiteId() {
     if (!plotinfo)
         return -1;
-    if (isFortressMode())
-        return plotinfo->site_id;
+    if (isFortressMode()) {
+        // on a reclaimed fortress, site_id isn't assigned until the first
+        // save; fortress_site is set at embark, so use it as a fallback
+        if (plotinfo->site_id >= 0)
+            return plotinfo->site_id;
+        if (auto site = plotinfo->main.fortress_site)
+            return site->id;
+        return -1;
+    }
     if (auto adv = getAdventurer(); adv && world->world_data) {
         DEBUG(world).print("searching for adventure site\n");
         auto & world_map = world->map;