--- a/xpcom/base/nsDebugImpl.cpp
+++ b/xpcom/base/nsDebugImpl.cpp
@@ -348,16 +348,19 @@ NS_DebugBreak(uint32_t aSeverity, const 
     PrintToBuffer("%s: ", aStr);
   }
   if (aExpr) {
     PrintToBuffer("'%s', ", aExpr);
   }
   if (aFile) {
     PrintToBuffer("file %s, ", aFile);
   }
+  if (aFunction) {
+    PrintToBuffer("function %s, ", aFunction);
+  }
   if (aLine != -1) {
     PrintToBuffer("line %d", aLine);
   }
 
 #  undef PrintToBuffer
 
   // errors on platforms without a debugdlg ring a bell on stderr
 #if !defined(XP_WIN)