diff --git a/Detectors/ITSMFT/ITS/base/include/ITSBase/GeometryTGeo.h b/Detectors/ITSMFT/ITS/base/include/ITSBase/GeometryTGeo.h
index 6172a02286abd..6d10a263408af 100644
--- a/Detectors/ITSMFT/ITS/base/include/ITSBase/GeometryTGeo.h
+++ b/Detectors/ITSMFT/ITS/base/include/ITSBase/GeometryTGeo.h
@@ -399,20 +399,20 @@ class GeometryTGeo : public o2::itsmft::GeometryTGeo
  protected:
   static constexpr int MAXLAYERS = 15; ///< max number of active layers
 
-  Int_t mNumberOfLayers;                        ///< number of layers
-  Int_t mNumberOfHalfBarrels;                   ///< number of halfbarrels
-  std::vector<int> mNumberOfStaves;             ///< number of staves/layer(layer)
-  std::vector<int> mNumberOfHalfStaves;         ///< the number of substaves/stave(layer)
-  std::vector<int> mNumberOfModules;            ///< number of modules/substave(layer)
-  std::vector<int> mNumberOfChipsPerModule;     ///< number of chips per module (group of chips on substaves)
-  std::vector<int> mNumberOfChipRowsPerModule;  ///< number of chips rows per module (relevant for OB modules)
-  std::vector<int> mNumberOfChipsPerHalfStave;  ///< number of chips per substave
-  std::vector<int> mNumberOfChipsPerStave;      ///< number of chips per stave
-  std::vector<int> mNumberOfChipsPerHalfBarrel; ///< number of chips per halfbarrel
-  std::vector<int> mNumberOfChipsPerLayer;      ///< number of chips per stave
-  std::vector<int> mLastChipIndex;              ///< max ID of the detctor in the layer
-  std::array<bool, MAXLAYERS> mIsLayerITS3;     ///< flag with the information of the ITS version (ITS2 or ITS3)
-  std::array<char, MAXLAYERS> mLayerToWrapper;  ///< Layer to wrapper correspondence
+  Int_t mNumberOfLayers;                         ///< number of layers
+  Int_t mNumberOfHalfBarrels;                    ///< number of halfbarrels
+  std::vector<int> mNumberOfStaves;              ///< number of staves/layer(layer)
+  std::vector<int> mNumberOfHalfStaves;          ///< the number of substaves/stave(layer)
+  std::vector<int> mNumberOfModules;             ///< number of modules/substave(layer)
+  std::vector<int> mNumberOfChipsPerModule;      ///< number of chips per module (group of chips on substaves)
+  std::vector<int> mNumberOfChipRowsPerModule;   ///< number of chips rows per module (relevant for OB modules)
+  std::vector<int> mNumberOfChipsPerHalfStave;   ///< number of chips per substave
+  std::vector<int> mNumberOfChipsPerStave;       ///< number of chips per stave
+  std::vector<int> mNumberOfChipsPerHalfBarrel;  ///< number of chips per halfbarrel
+  std::vector<int> mNumberOfChipsPerLayer;       ///< number of chips per stave
+  std::vector<int> mLastChipIndex;               ///< max ID of the detctor in the layer
+  std::array<bool, MAXLAYERS> mIsLayerITS3;      ///< flag with the information of the ITS version (ITS2 or ITS3)
+  std::array<int8_t, MAXLAYERS> mLayerToWrapper; ///< Layer to wrapper correspondence
 
   std::vector<float> mCacheRefX;     ///< sensors tracking plane reference X
   std::vector<float> mCacheRefAlpha; ///< sensors tracking plane reference alpha
diff --git a/Detectors/PHOS/reconstruction/src/Clusterer.cxx b/Detectors/PHOS/reconstruction/src/Clusterer.cxx
index 08b8ddfd234a5..57e008e197ccc 100644
--- a/Detectors/PHOS/reconstruction/src/Clusterer.cxx
+++ b/Detectors/PHOS/reconstruction/src/Clusterer.cxx
@@ -235,7 +235,7 @@ void Clusterer::makeUnfolding(Cluster& clu, std::vector<Cluster>& clusters, std:
     return;
   }
 
-  char nMax = getNumberOfLocalMax(clu, cluelements);
+  int8_t nMax = getNumberOfLocalMax(clu, cluelements);
   if (nMax > 1) {
     unfoldOneCluster(clu, nMax, clusters, cluelements);
   } else {
@@ -250,7 +250,7 @@ void Clusterer::makeUnfolding(Cluster& clu, std::vector<Cluster>& clusters, std:
   }
 }
 //____________________________________________________________________________
-void Clusterer::unfoldOneCluster(Cluster& iniClu, char nMax, std::vector<Cluster>& clusters, std::vector<CluElement>& cluelements)
+void Clusterer::unfoldOneCluster(Cluster& iniClu, int8_t nMax, std::vector<Cluster>& clusters, std::vector<CluElement>& cluelements)
 {
   // Performs the unfolding of a cluster with nMax overlapping showers
   // Parameters: iniClu cluster to be unfolded
diff --git a/Detectors/TRD/base/include/TRDBase/ChamberStatus.h b/Detectors/TRD/base/include/TRDBase/ChamberStatus.h
index b5e1afd9d98f9..ab0128f0a4b11 100644
--- a/Detectors/TRD/base/include/TRDBase/ChamberStatus.h
+++ b/Detectors/TRD/base/include/TRDBase/ChamberStatus.h
@@ -46,7 +46,7 @@ class ChamberStatus
   ChamberStatus() = default;
   ~ChamberStatus() = default;
   //
-  char getStatus(int det) const { return mStatus[det]; }
+  int8_t getStatus(int det) const { return mStatus[det]; }
   void setStatus(int det, char bit);
   void setRawStatus(int det, char status) { mStatus[det] = status; };
   bool isGood(int det) const { return (mStatus[det] & Good); }
@@ -61,7 +61,7 @@ class ChamberStatus
   TH2D* plotBadCalibrated(int sm, int rphi); // Plot calibration status for sm and halfchamberside
   TH2D* plot(int sm);                        // Plot mStatus for sm
  private:
-  std::array<char, constants::MAXCHAMBER> mStatus{};
+  std::array<int8_t, constants::MAXCHAMBER> mStatus{};
   ClassDefNV(ChamberStatus, 1);
 };
 } // namespace trd