diff --git a/core/metacling/src/TCling.cxx b/core/metacling/src/TCling.cxx
index c52794664083c..62efdcca03a7c 100644
--- a/core/metacling/src/TCling.cxx
+++ b/core/metacling/src/TCling.cxx
@@ -5484,7 +5484,7 @@ Longptr_t TCling::ExecuteMacro(const char* filename, EErrorCode* error)
 const char* TCling::GetTopLevelMacroName() const
 {
    Warning("GetTopLevelMacroName", "Must change return type!");
-   return fCurExecutingMacros.back();
+   return fCurExecutingMacros.empty() ? nullptr : fCurExecutingMacros.back();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -5535,7 +5535,7 @@ const char* TCling::GetCurrentMacroName() const
    Warning("GetCurrentMacroName", "Must change return type!");
 #endif
 #endif
-   return fCurExecutingMacros.back();
+   return fCurExecutingMacros.empty() ? nullptr : fCurExecutingMacros.back();
 }
 
 ////////////////////////////////////////////////////////////////////////////////