diff --git a/llvm/lib/TableGen/TGParser.cpp b/llvm/lib/TableGen/TGParser.cpp
--- a/llvm/lib/TableGen/TGParser.cpp
+++ b/llvm/lib/TableGen/TGParser.cpp
@@ -2539,9 +2539,9 @@
 
     if (consume(tgtok::greater)) // end of argument list?
       return false;
-    if (!consume(tgtok::comma)) // must be comma
-      return true;
-    ++ArgIndex; 
+    if (!consume(tgtok::comma))
+      return TokError("Expected comma before next argument");
+    ++ArgIndex;
   }
 }
 
diff --git a/llvm/test/TableGen/template-args.td b/llvm/test/TableGen/template-args.td
--- a/llvm/test/TableGen/template-args.td
+++ b/llvm/test/TableGen/template-args.td
@@ -5,6 +5,7 @@
 // RUN: not llvm-tblgen -DERROR4 %s 2>&1 | FileCheck --check-prefix=ERROR4 %s
 // RUN: not llvm-tblgen -DERROR5 %s 2>&1 | FileCheck --check-prefix=ERROR5 %s
 // RUN: not llvm-tblgen -DERROR6 %s 2>&1 | FileCheck --check-prefix=ERROR6 %s
+// RUN: not llvm-tblgen -DERROR7 %s 2>&1 | FileCheck --check-prefix=ERROR7 %s
 
 // This file tests that template arguments are type-checked and cast
 // if necessary.
@@ -140,3 +141,13 @@
 
 defm RecMC4 : MC2<"Bob">;
 #endif
+
+#ifdef ERROR7
+multiclass TwoArgs<bits<8> a, string b> {
+  def _1 { bits<8> A = a; }
+  def _2 { string B = b; }
+}
+defm Good : TwoArgs<1, "one">;
+defm MissingComma : TwoArgs<2 "two">;
+// ERROR7: [[#@LINE-1]]:31: error: Expected comma before next argument
+#endif