diff --git a/include/util/mmap_tar.hpp b/include/util/mmap_tar.hpp
new file mode 100644
index 000000000..b9129ba87
--- /dev/null
+++ b/include/util/mmap_tar.hpp
@@ -0,0 +1,44 @@
+#ifndef OSRM_UTIL_MMAP_TAR_HPP
+#define OSRM_UTIL_MMAP_TAR_HPP
+
+#include "storage/tar.hpp"
+
+#include "util/mmap_file.hpp"
+
+#include <boost/iostreams/device/mapped_file.hpp>
+
+#include <tuple>
+#include <unordered_map>
+
+namespace osrm
+{
+namespace util
+{
+using DataRange = std::pair<const char *, const char *>;
+using DataMap = std::unordered_map<std::string, DataRange>;
+
+inline DataMap mmapTarFile(const boost::filesystem::path &path,
+                           boost::iostreams::mapped_file_source &region)
+{
+    DataMap map;
+
+    storage::tar::FileReader reader{path, storage::tar::FileReader::VerifyFingerprint};
+
+    std::vector<storage::tar::FileReader::FileEntry> entries;
+    reader.List(std::back_inserter(entries));
+
+    auto raw_file = mmapFile<char>(path, region);
+
+    for (const auto &entry : entries)
+    {
+        auto begin = raw_file.data() + entry.offset;
+        auto end = begin + entry.size;
+        map[entry.name] = DataRange{begin, end};
+    }
+
+    return map;
+}
+}
+}
+
+#endif
diff --git a/src/updater/updater.cpp b/src/updater/updater.cpp
index ffebb7fcf..bb2a7188d 100644
--- a/src/updater/updater.cpp
+++ b/src/updater/updater.cpp
@@ -18,6 +18,7 @@
 #include "util/for_each_pair.hpp"
 #include "util/integer_range.hpp"
 #include "util/log.hpp"
+#include "util/mmap_tar.hpp"
 #include "util/opening_hours.hpp"
 #include "util/static_graph.hpp"
 #include "util/static_rtree.hpp"
@@ -435,8 +436,13 @@ updateTurnPenalties(const UpdaterConfig &config,
 
     // Mapped file pointer for turn indices
     boost::iostreams::mapped_file_source turn_index_region;
-    auto turn_index_blocks = util::mmapFile<extractor::lookup::TurnIndexBlock>(
-        config.GetPath(".osrm.turn_penalties_index"), turn_index_region);
+    const extractor::lookup::TurnIndexBlock *turn_index_blocks;
+    {
+        auto map =
+            util::mmapTarFile(config.GetPath(".osrm.turn_penalties_index"), turn_index_region);
+        turn_index_blocks =
+            reinterpret_cast<const extractor::lookup::TurnIndexBlock *>(map["/extractor/turn_index"].first);
+    }
 
     // Get the turn penalty and update to the new value if required
     std::vector<std::uint64_t> updated_turns;