diff --git a/algo/detectors/tof/Calibrate.cxx b/algo/detectors/tof/Calibrate.cxx
index 944677547755d5936384815daded940795d6f88e..1da478be01e7795369429016236437cc7eac488d 100644
--- a/algo/detectors/tof/Calibrate.cxx
+++ b/algo/detectors/tof/Calibrate.cxx
@@ -28,7 +28,7 @@ namespace cbm::algo::tof
     calDigiOut.reserve(digiIn.size());
 
     // channel deadtime map
-    std::map<int32_t, double> mChannelDeadTime;
+    std::unordered_map<int32_t, double> mChannelDeadTime;
 
     for (size_t iDigi = 0; iDigi < digiIn.size(); iDigi++) {