diff --git a/3rdparty/lmdb-safe b/3rdparty/lmdb-safe
index 4580d72..95ff695 160000
--- a/3rdparty/lmdb-safe
+++ b/3rdparty/lmdb-safe
@@ -1 +1 @@
-Subproject commit 4580d7242ad2c1c56582c6ee25e2227bfc6166e7
+Subproject commit 95ff695381c9662ec100697bebc6132bc317c005
diff --git a/librepomgr/buildactions/buildactionmeta.h b/librepomgr/buildactions/buildactionmeta.h
index 427c728..94078bf 100644
--- a/librepomgr/buildactions/buildactionmeta.h
+++ b/librepomgr/buildactions/buildactionmeta.h
@@ -47,6 +47,7 @@ enum class BuildActionType : std::uint64_t {
     CleanRepository,
     DummyBuildAction,
     CustomCommand,
+    LastType = CustomCommand,
 };
 
 using BuildActionFlagType = std::uint64_t;
diff --git a/librepomgr/serversetup.cpp b/librepomgr/serversetup.cpp
index cace8eb..55a24ef 100644
--- a/librepomgr/serversetup.cpp
+++ b/librepomgr/serversetup.cpp
@@ -357,6 +357,41 @@ std::size_t ServiceSetup::BuildSetup::buildActionCount()
     return m_storage->buildActions.getROTransaction().size();
 }
 
+void ServiceSetup::BuildSetup::rebuildDb()
+{
+    auto txn = m_storage->buildActions.getRWTransaction();
+    auto processed = std::size_t();
+    auto ok = std::size_t();
+    txn.rebuild([count = txn.size(), &processed, &ok](StorageID id, BuildAction *buildAction) mutable {
+        std::cerr << "Processing build action " << ++processed << " / " << count << '\n';
+        if (!buildAction) {
+            std::cerr << "Deleting build action " << id << ": unable to deserialize\n";
+            return false;
+        }
+        if (buildAction->id > std::numeric_limits<StorageID>::max()) {
+            std::cerr << "Deleting build action " << id << ": object ID " << buildAction->id << " is out of range\n";
+            return false;
+        }
+        if (buildAction->id != id) {
+            std::cerr << "Deleting build action " << id << ": ID mismatch (object ID is " << buildAction->id << ")\n";
+            return false;
+        }
+        if (buildAction->type == BuildActionType::Invalid || buildAction->type > BuildActionType::LastType) {
+            std::cerr << "Deleting build action " << id << ": type is invalid\n";
+            return false;
+        }
+        ++ok;
+        return true;
+    });
+    if (ok < processed) {
+        std::cerr << "Discarding " << (processed - ok) << " invalid build actions.\n";
+    } else {
+        std::cerr << "All " << ok << " build actions are valid.\n";
+    }
+    std::cerr << "Committing changes.\n";
+    txn.commit();
+}
+
 void ServiceSetup::BuildSetup::forEachBuildAction(
     std::function<void(std::size_t)> count, std::function<bool(LibPkg::StorageID, BuildAction &&)> &&func, std::size_t limit, std::size_t start)
 {
@@ -764,6 +799,26 @@ int ServiceSetup::run()
     return 0;
 }
 
+int ServiceSetup::fixDb()
+{
+#ifndef CPP_UTILITIES_DEBUG_BUILD
+    try {
+#endif
+        loadConfigFiles(true);
+        building.initStorage(building.dbPath.data());
+        building.rebuildDb();
+#ifndef CPP_UTILITIES_DEBUG_BUILD
+    } catch (const std::exception &e) {
+        cerr << Phrases::ErrorMessage << "Exception occurred when terminating server: " << Phrases::End << "  " << e.what() << Phrases::EndFlush;
+        return -5;
+    } catch (...) {
+        cerr << Phrases::ErrorMessage << "Unknown error occurred when terminating server." << Phrases::EndFlush;
+        return -6;
+    }
+#endif
+    return 0;
+}
+
 void ServiceSetup::Locks::clear()
 {
     auto log = LogContext();
diff --git a/librepomgr/serversetup.h b/librepomgr/serversetup.h
index c720e19..4e2f1e0 100644
--- a/librepomgr/serversetup.h
+++ b/librepomgr/serversetup.h
@@ -55,6 +55,7 @@ struct LIBREPOMGR_EXPORT ServiceSetup : public LibPkg::Lockable {
     std::size_t saveState();
     void initStorage();
     int run();
+    int fixDb();
     ServiceStatus computeStatus() const;
 
     // variables relevant for the web server; only changed when (re)loading config
@@ -141,6 +142,7 @@ struct LIBREPOMGR_EXPORT ServiceSetup : public LibPkg::Lockable {
         void deleteBuildAction(const std::vector<std::shared_ptr<BuildAction>> &actions);
         std::size_t buildActionCount();
         std::size_t runningBuildActionCount();
+        void rebuildDb();
         void forEachBuildAction(std::function<void(std::size_t)> count, std::function<bool(LibPkg::StorageID, BuildAction &&)> &&func,
             std::size_t limit, std::size_t start);
         void forEachBuildAction(std::function<bool(LibPkg::StorageID, BuildAction &, bool &)> &&func);
diff --git a/srv/main.cpp b/srv/main.cpp
index 14c0447..dea7188 100644
--- a/srv/main.cpp
+++ b/srv/main.cpp
@@ -41,9 +41,17 @@ int main(int argc, const char *argv[])
         setup.building.forceLoadingDbs = forceLoadingDBsArg.isPresent();
         exitCode = setup.run();
     });
+    OperationArgument fixDb("fix-db", '\0', "fixes the database files");
+    fixDb.setSubArguments({ &configFileArg });
+    fixDb.setCallback([&setup, &exitCode, &configFileArg](const ArgumentOccurrence &) {
+        if (const auto configFilePath = configFileArg.firstValue()) {
+            setup.configFilePath = configFilePath;
+        }
+        exitCode = setup.fixDb();
+    });
     HelpArgument helpArg(parser);
     NoColorArgument noColorArg;
-    parser.setMainArguments({ &runArg, &noColorArg, &helpArg });
+    parser.setMainArguments({ &runArg, &fixDb, &noColorArg, &helpArg });
     parser.setDefaultArgument(&runArg);
     parser.parseArgs(argc, argv);
     return exitCode;