diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -901,8 +901,9 @@
   }
 
   if (sym.getName().startswith("_ZTV"))
-    msg += "\nthe vtable symbol may be undefined because the class is missing "
-           "its key function (see https://lld.llvm.org/missingkeyfunction)";
+    msg +=
+        "\n>>> the vtable symbol may be undefined because the class is missing "
+        "its key function (see https://lld.llvm.org/missingkeyfunction)";
 
   if (undef.isWarning)
     warn(msg);
diff --git a/lld/test/ELF/undef.s b/lld/test/ELF/undef.s
--- a/lld/test/ELF/undef.s
+++ b/lld/test/ELF/undef.s
@@ -25,7 +25,7 @@
 # CHECK:      error: undefined symbol: vtable for Foo 
 # CHECK-NEXT: >>> referenced by undef.s
 # CHECK-NEXT: >>>               {{.*}}:(.text+0x15)
-# CHECK-NEXT: the vtable symbol may be undefined because the class is missing its key function (see https://lld.llvm.org/missingkeyfunction)
+# CHECK-NEXT: >>> the vtable symbol may be undefined because the class is missing its key function (see https://lld.llvm.org/missingkeyfunction)
 
 # Check that this symbol isn't demangled