diff --git a/src/ZoneCommon/Zone/XChunk/XChunkProcessorInflate.cpp b/src/ZoneCommon/Zone/XChunk/XChunkProcessorInflate.cpp
index 9d1058ce..bf3b0880 100644
--- a/src/ZoneCommon/Zone/XChunk/XChunkProcessorInflate.cpp
+++ b/src/ZoneCommon/Zone/XChunk/XChunkProcessorInflate.cpp
@@ -27,7 +27,7 @@ size_t XChunkProcessorInflate::Process(unsigned streamNumber, const uint8_t* inp
     ret = inflate(&stream, Z_FULL_FLUSH);
     if (ret != Z_STREAM_END)
     {
-        con::error("inflate of stream failed with error code {}: {}", streamNumber, ret, stream.msg);
+        con::error("inflate of stream {} failed with error code {}: {}", streamNumber, ret, stream.msg);
         throw XChunkException(std::format("Zone has invalid or unsupported compression: {}", stream.msg));
     }
 
diff --git a/test/SystemTests/RebuildVanillaZonesTests.cpp b/test/SystemTests/RebuildVanillaZonesTests.cpp
new file mode 100644
index 00000000..82fa2567
--- /dev/null
+++ b/test/SystemTests/RebuildVanillaZonesTests.cpp
@@ -0,0 +1,96 @@
+#include "Game/T6/GameAssetPoolT6.h"
+#include "OatTestPaths.h"
+#include "Utils/Logging/Log.h"
+#include "Utils/StringUtils.h"
+#include "ZoneLoading.h"
+#include "ZoneWriting.h"
+
+#include <catch2/catch_test_macros.hpp>
+#include <filesystem>
+#include <format>
+#include <fstream>
+#include <memory>
+#include <string>
+
+namespace fs = std::filesystem;
+using namespace std::literals;
+
+/*
+ * This test is only run when the user defines the environment variable OAT_FASTFILE_DIR containing the path to a folder containing fastfiles.
+ */
+namespace
+{
+    void EnsureCanRebuildFastFile(const fs::path& outputPath, const fs::path& fastFilePath)
+    {
+        const auto fastFilePathStr = fastFilePath.string();
+        const auto tempFilePath = outputPath / "temp.ff";
+        const auto tempFilePathStr = tempFilePath.string();
+
+        con::info("Testing for rebuild: {}", fastFilePathStr);
+
+        auto maybeZone = ZoneLoading::LoadZone(fastFilePathStr, std::nullopt);
+        REQUIRE(maybeZone.has_value());
+
+        auto zone = std::move(*maybeZone);
+        zone->m_name = "temp";
+
+        {
+            std::ofstream outStream(tempFilePath, std::ios::out | std::ios::binary);
+            REQUIRE(outStream.is_open());
+
+            const auto linkingResult = ZoneWriting::WriteZone(outStream, *zone);
+            REQUIRE(linkingResult);
+        }
+
+        auto maybeRebuiltZone = ZoneLoading::LoadZone(tempFilePathStr, std::nullopt);
+        REQUIRE(maybeRebuiltZone.has_value());
+
+        auto rebuiltZone = std::move(*maybeRebuiltZone);
+
+        const auto& pools = *zone->m_pools;
+        const auto& rebuiltPools = *rebuiltZone->m_pools;
+
+        const auto totalAssetCount = pools.GetTotalAssetCount();
+        REQUIRE(totalAssetCount == rebuiltPools.GetTotalAssetCount());
+
+        auto zoneIter = pools.begin();
+        auto zoneEnd = pools.end();
+        auto rebuiltZoneIter = rebuiltPools.begin();
+        auto rebuiltZoneEnd = rebuiltPools.end();
+
+        while (zoneIter != zoneEnd)
+        {
+            REQUIRE(rebuiltZoneIter != rebuiltZoneEnd);
+
+            REQUIRE((*zoneIter)->m_type == (*rebuiltZoneIter)->m_type);
+            REQUIRE((*zoneIter)->m_name == (*rebuiltZoneIter)->m_name);
+
+            ++zoneIter;
+            ++rebuiltZoneIter;
+        }
+    }
+
+    TEST_CASE("Rebuild vanilla zones", "[custom]")
+    {
+        auto* fastFilePathStr = std::getenv("OAT_FASTFILE_DIR");
+        if (!fastFilePathStr)
+            return;
+
+        const auto outputPath = oat::paths::GetTempDirectory("RebuildVanillaZones");
+        const fs::path fastFilePath(fastFilePathStr);
+
+        fs::directory_iterator iterator(fastFilePath);
+        const auto end = fs::end(iterator);
+        for (auto i = fs::begin(iterator); i != end; ++i)
+        {
+            if (!i->is_regular_file())
+                continue;
+
+            const auto path = i->path();
+            auto extension = path.extension().string();
+            utils::MakeStringLowerCase(extension);
+            if (extension == ".ff")
+                EnsureCanRebuildFastFile(outputPath, path);
+        }
+    }
+} // namespace