Index: llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll
===================================================================
--- llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll
+++ llvm/trunk/test/LTO/X86/diagnostic-handler-remarks.ll
@@ -9,7 +9,7 @@
 
 ; RUN: llvm-lto -pass-remarks=inline -use-diagnostic-handler \
 ; RUN:         -exported-symbol _main -o %t.o %t.bc 2>&1 | \
-; RUN:     FileCheck %s -allow-empty -check-prefix=REMARKS
+; RUN:     FileCheck %s -allow-empty -check-prefix=REMARKS_DH
 ; RUN: llvm-nm %t.o | FileCheck %s -check-prefix NM
 
 ; Confirm that -pass-remarks are not printed by default.
@@ -24,7 +24,9 @@
 ; RUN: llvm-nm %t.o | FileCheck %s -check-prefix NM
 
 ; REMARKS: remark:
+; REMARKS_DH: llvm-lto: remark:
 ; CHECK-NOT: remark:
+; CHECK-NOT: llvm-lto:
 ; NM-NOT: foo
 ; NM: main
 
Index: llvm/trunk/tools/llvm-lto/llvm-lto.cpp
===================================================================
--- llvm/trunk/tools/llvm-lto/llvm-lto.cpp
+++ llvm/trunk/tools/llvm-lto/llvm-lto.cpp
@@ -101,6 +101,7 @@
 
 static void handleDiagnostics(lto_codegen_diagnostic_severity_t Severity,
                               const char *Msg, void *) {
+  errs() << "llvm-lto: ";
   switch (Severity) {
   case LTO_DS_NOTE:
     errs() << "note: ";