diff --git a/mlir/test/lib/Dialect/Test/TestDialect.h b/mlir/test/lib/Dialect/Test/TestDialect.h
--- a/mlir/test/lib/Dialect/Test/TestDialect.h
+++ b/mlir/test/lib/Dialect/Test/TestDialect.h
@@ -45,11 +45,9 @@
 #define GET_OP_CLASSES
 #include "TestOps.h.inc"
 
-namespace mlir {
 namespace test {
 void registerTestDialect(DialectRegistry &registry);
 void populateTestReductionPatterns(RewritePatternSet &patterns);
-} // namespace test
-} // namespace mlir
+} // end namespace test
 
 #endif // MLIR_TESTDIALECT_H
diff --git a/mlir/test/lib/Dialect/Test/TestDialect.cpp b/mlir/test/lib/Dialect/Test/TestDialect.cpp
--- a/mlir/test/lib/Dialect/Test/TestDialect.cpp
+++ b/mlir/test/lib/Dialect/Test/TestDialect.cpp
@@ -22,12 +22,11 @@
 #include "mlir/Transforms/InliningUtils.h"
 #include "llvm/ADT/StringSwitch.h"
 
-using namespace mlir;
-using namespace mlir::test;
-
 #include "TestOpsDialect.cpp.inc"
 
-void mlir::test::registerTestDialect(DialectRegistry &registry) {
+using namespace mlir;
+
+void test::registerTestDialect(DialectRegistry &registry) {
   registry.insert<TestDialect>();
 }
 
diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -24,7 +24,7 @@
 
 def Test_Dialect : Dialect {
   let name = "test";
-  let cppNamespace = "::mlir::test";
+  let cppNamespace = "::test";
   let hasCanonicalizer = 1;
   let hasConstantMaterializer = 1;
   let hasOperationAttrVerify = 1;
@@ -117,8 +117,8 @@
 }
 
 def TEST_TestType : DialectType<Test_Dialect,
-    CPred<"$_self.isa<::mlir::test::TestType>()">, "test">,
-    BuildableType<"$_builder.getType<::mlir::test::TestType>()">;
+    CPred<"$_self.isa<::test::TestType>()">, "test">,
+    BuildableType<"$_builder.getType<::test::TestType>()">;
 
 //===----------------------------------------------------------------------===//
 // Test Symbols
diff --git a/mlir/test/lib/Dialect/Test/TestTypes.h b/mlir/test/lib/Dialect/Test/TestTypes.h
--- a/mlir/test/lib/Dialect/Test/TestTypes.h
+++ b/mlir/test/lib/Dialect/Test/TestTypes.h
@@ -23,7 +23,6 @@
 #include "mlir/IR/Types.h"
 #include "mlir/Interfaces/DataLayoutInterfaces.h"
 
-namespace mlir {
 namespace test {
 
 /// FieldInfo represents a field in the StructType data type. It is used as a
@@ -98,6 +97,5 @@
 };
 
 } // namespace test
-} // namespace mlir
 
 #endif // MLIR_TESTTYPES_H