diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index ae007ce3693..9e699d1ed3f 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2968,8 +2968,8 @@ bool LLParser::ParseMetadataAsValue(ValID &ID, PerFunctionState *PFS) {
 ///  ::= !{...}
 ///  ::= !"string"
 bool LLParser::ParseMetadata(Metadata *&MD, PerFunctionState *PFS) {
-  assert(Lex.getKind() == lltok::exclaim);
-  Lex.Lex();
+  if (ParseToken(lltok::exclaim, "expected '!' here"))
+    return true;
 
   // MDNode:
   // !{ ... }
diff --git a/test/Assembler/invalid-mdnode-vector2.ll b/test/Assembler/invalid-mdnode-vector2.ll
new file mode 100644
index 00000000000..3b577bba6cf
--- /dev/null
+++ b/test/Assembler/invalid-mdnode-vector2.ll
@@ -0,0 +1,4 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+!0 = metadata !{metadata
+; CHECK: expected '!' here