diff --git a/mlir/tools/mlir-tblgen/OpDocGen.cpp b/mlir/tools/mlir-tblgen/OpDocGen.cpp
--- a/mlir/tools/mlir-tblgen/OpDocGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDocGen.cpp
@@ -221,7 +221,12 @@
 static void emitDialectDoc(const Dialect &dialect, ArrayRef<Operator> ops,
                            ArrayRef<Type> types, ArrayRef<TypeDef> typeDefs,
                            raw_ostream &os) {
-  os << "# '" << dialect.getName() << "' Dialect\n\n";
+  os << "# '";
+  if (dialect.getName().empty())
+    os << "Builtin";
+  else
+    os << dialect.getName();
+  os << "' Dialect\n\n";
   emitIfNotEmpty(dialect.getSummary(), os);
   emitIfNotEmpty(dialect.getDescription(), os);