diff --git a/src/external/MusrRoot/TMusrRunHeader.cpp b/src/external/MusrRoot/TMusrRunHeader.cpp
index 58872ba3..dab7e10f 100644
--- a/src/external/MusrRoot/TMusrRunHeader.cpp
+++ b/src/external/MusrRoot/TMusrRunHeader.cpp
@@ -394,6 +394,68 @@ Bool_t TMusrRunHeader::FillFolder(TFolder *folder)
   return true;
 }
 
+//--------------------------------------------------------------------------
+// GetTypeOfPath (public)
+//--------------------------------------------------------------------------
+/**
+ * <p>Get type of path-name, e.g. RunInfo/Sample Name.
+ *
+ * @param pathName path-name for which the type is requested
+ *
+ * @return the type, or 'undef' if path-name is not found.
+ */
+TString TMusrRunHeader::GetTypeOfPath(TString pathName)
+{
+  TString type("undef");
+
+  // find pathName
+  for (Int_t i=0; i<fStringObj.size(); i++) {
+    if (fStringObj[i].GetPathName() == pathName) {
+      type = fStringObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fIntObj.size(); i++) {
+    if (fIntObj[i].GetPathName() == pathName) {
+      type = fIntObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fDoubleObj.size(); i++) {
+    if (fDoubleObj[i].GetPathName() == pathName) {
+      type = fDoubleObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fMusrRunPhysQuantityObj.size(); i++) {
+    if (fMusrRunPhysQuantityObj[i].GetPathName() == pathName) {
+      type = fMusrRunPhysQuantityObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fStringVectorObj.size(); i++) {
+    if (fStringVectorObj[i].GetPathName() == pathName) {
+      type = fStringVectorObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fIntVectorObj.size(); i++) {
+    if (fIntVectorObj[i].GetPathName() == pathName) {
+      type = fIntVectorObj[i].GetType();
+      return type;
+    }
+  }
+  for (Int_t i=0; i<fDoubleVectorObj.size(); i++) {
+    if (fDoubleVectorObj[i].GetPathName() == pathName) {
+      type = fDoubleVectorObj[i].GetType();
+      return type;
+    }
+  }
+
+
+  return type;
+}
+
 //--------------------------------------------------------------------------
 // Get (public)
 //--------------------------------------------------------------------------
diff --git a/src/external/MusrRoot/TMusrRunHeader.h b/src/external/MusrRoot/TMusrRunHeader.h
index 904883d0..b0710038 100644
--- a/src/external/MusrRoot/TMusrRunHeader.h
+++ b/src/external/MusrRoot/TMusrRunHeader.h
@@ -133,6 +133,8 @@ public:
   virtual Bool_t ExtractAll(TFolder *folder);
   virtual Bool_t ExtractHeaderInformation(TObjArray *headerInfo, TString path);
 
+  virtual TString GetTypeOfPath(TString pathName);
+
   virtual void Get(TString pathName, TString &value, Bool_t &ok);
   virtual void Get(TString pathName, Int_t &value, Bool_t &ok);
   virtual void Get(TString pathName, Double_t &value, Bool_t &ok);
diff --git a/src/musredit_qt5/musredit/CMakeLists.txt b/src/musredit_qt5/musredit/CMakeLists.txt
index bcb0b2b2..a3d4d920 100644
--- a/src/musredit_qt5/musredit/CMakeLists.txt
+++ b/src/musredit_qt5/musredit/CMakeLists.txt
@@ -88,8 +88,14 @@ set_property(SOURCE ui_PMsr2DataDialog.h PROPERTY SKIP_AUTOMOC ON)
 set_property(SOURCE ui_PChangeDefaultPathsDialog.h PROPERTY SKIP_AUTOMOC ON)
 set_property(SOURCE qrc_musredit.cpp PROPERTY SKIP_AUTOMOC ON)
 
-set(macosx_icon icons/musredit.icns)
 if (APPLE)
+  if (${CMAKE_HOST_SYSTEM_VERSION} GREATER_EQUAL "20.3.0")
+    set(macosx_icon_name musredit-bigsur.icns)
+  else()	
+    set(macosx_icon_name musredit.icns)
+  endif()
+  set(macosx_icon "icons/${macosx_icon_name}")
+message(STATUS "macosx_icon: ${macosx_icon}")
   add_executable(musredit MACOSX_BUNDLE
     ${musredit_src}
     ${out_ui}
@@ -144,7 +150,7 @@ if (APPLE)
     MACOSX_BUNDLE TRUE
     MACOSX_BUNDLE_BUNDLE_NAME "musredit"
     MACOSX_BUNDLE_INFO_STRING "musrfit: musredit simplifies the handling of the msr-files for uSR fitting."
-    MACOSX_BUNDLE_ICON_FILE "musredit.icns"
+    MACOSX_BUNDLE_ICON_FILE "${macosx_icon_name}"
     MACOSX_BUNDLE_LONG_VERSION_STRING "${PROJECT_VERSION}"
     MACOSX_BUNDLE_GUI_IDENTIFIER "ch.psi.lmu.musredit"
     MACOSX_BUNDLE_COPYRIGHT "Andreas Suter"
diff --git a/src/musredit_qt5/musredit/icons/musredit-bigsur.icns b/src/musredit_qt5/musredit/icons/musredit-bigsur.icns
new file mode 100644
index 00000000..7de4b246
Binary files /dev/null and b/src/musredit_qt5/musredit/icons/musredit-bigsur.icns differ
diff --git a/src/musredit_qt6/musredit/CMakeLists.txt b/src/musredit_qt6/musredit/CMakeLists.txt
index e3986681..eae972a7 100644
--- a/src/musredit_qt6/musredit/CMakeLists.txt
+++ b/src/musredit_qt6/musredit/CMakeLists.txt
@@ -84,8 +84,13 @@ set_property(SOURCE ui_PMsr2DataDialog.h PROPERTY SKIP_AUTOMOC ON)
 set_property(SOURCE ui_PChangeDefaultPathsDialog.h PROPERTY SKIP_AUTOMOC ON)
 set_property(SOURCE qrc_musredit.cpp PROPERTY SKIP_AUTOMOC ON)
 
-set(macosx_icon icons/musredit.icns)
 if (APPLE)
+  if (${CMAKE_HOST_SYSTEM_VERSION} GREATER_EQUAL "20.3.0")
+    set(macosx_icon_name musredit-bigsur.icns)
+  else()
+    set(macosx_icon_name musredit.icns)
+  endif()
+  set(macosx_icon "icons/${macosx_icon_name}")      	
   add_executable(musredit MACOSX_BUNDLE
     ${musredit_src}
     ${out_ui}
@@ -117,7 +122,7 @@ if (APPLE)
     MACOSX_BUNDLE TRUE
     MACOSX_BUNDLE_BUNDLE_NAME "musredit"
     MACOSX_BUNDLE_INFO_STRING "musrfit: musredit simplifies the handling of the msr-files for uSR fitting."
-    MACOSX_BUNDLE_ICON_FILE "musredit.icns"
+    MACOSX_BUNDLE_ICON_FILE "${macosx_icon_name}"
     MACOSX_BUNDLE_LONG_VERSION_STRING "${PROJECT_VERSION}"
     MACOSX_BUNDLE_GUI_IDENTIFIER "ch.psi.lmu.musredit"
     MACOSX_BUNDLE_COPYRIGHT "Andreas Suter"
diff --git a/src/musredit_qt6/musredit/icons/musredit-bigsur.icns b/src/musredit_qt6/musredit/icons/musredit-bigsur.icns
new file mode 100644
index 00000000..7de4b246
Binary files /dev/null and b/src/musredit_qt6/musredit/icons/musredit-bigsur.icns differ