diff --git a/src/classes/PMsrHandler.cpp b/src/classes/PMsrHandler.cpp
index 9e6d2715..49d3a437 100644
--- a/src/classes/PMsrHandler.cpp
+++ b/src/classes/PMsrHandler.cpp
@@ -1110,8 +1110,8 @@ void PMsrHandler::SetMsrDataRangeEntry(UInt_t runNo, UInt_t idx, Int_t bin)
     return;
   }
 
-  if ((idx < 0) || (idx > fRuns[runNo].GetDataRangeSize())) { // error
-    cerr << endl << "PMsrHandler::SetMsrDataRangeEntry: **ERROR** idx = " << idx << ", is out of valid range 0.." << fRuns[runNo].GetDataRangeSize();
+  if (idx < 0) { // error
+    cerr << endl << "PMsrHandler::SetMsrDataRangeEntry: **ERROR** idx = " << idx << ", is out of valid range, i.e. idx >= 0 needed.";
     cerr << endl;
     return;
   }
@@ -1137,8 +1137,8 @@ void PMsrHandler::SetMsrBkgRangeEntry(UInt_t runNo, UInt_t idx, Int_t bin)
     return;
   }
 
-  if ((idx < 0) || (idx > fRuns[runNo].GetBkgRangeSize())) { // error
-    cerr << endl << "PMsrHandler::SetMsrBkgRangeEntry: idx = " << idx << ", is out of valid range 0.." << fRuns[runNo].GetBkgRangeSize();
+  if (idx < 0) { // error
+    cerr << endl << "PMsrHandler::SetMsrBkgRangeEntry: idx = " << idx << ", is out of valid range, i.e. idx >= 0 needed.";
     cerr << endl;
     return;
   }
diff --git a/src/classes/PMusr.cpp b/src/classes/PMusr.cpp
index 24aaf4aa..9319b448 100644
--- a/src/classes/PMusr.cpp
+++ b/src/classes/PMusr.cpp
@@ -773,8 +773,7 @@ void PMsrRunBlock::SetBkgFix(Double_t dval, UInt_t idx)
 Int_t PMsrRunBlock::GetBkgRange(UInt_t i)
 {
   if (i > fBkgRange.size()) {
-    cerr << endl << ">> PMsrRunBlock::GetBkgRange: **ERROR** index i=" << i << " out of range, fatal." << endl;
-    assert(0);
+    return -1;
   }
 
   return fBkgRange[i];
@@ -807,8 +806,7 @@ void PMsrRunBlock::SetBkgRange(Int_t ival, UInt_t idx)
 Int_t PMsrRunBlock::GetDataRange(UInt_t i)
 {
   if (i > fDataRange.size()) {
-    cerr << endl << ">> PMsrRunBlock::GetDataRange: **ERROR** index i=" << i << " out of range, fatal." << endl;
-    assert(0);
+    return -1;
   }
 
   return fDataRange[i];