diff --git a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
index 69d6e9774942b..305a06427ed0e 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIRDialect.td
@@ -22,7 +22,7 @@ def CIR_Dialect : Dialect {
   let summary = "A high-level dialect for analyzing and optimizing Clang "
                 "supported languages";
 
-  let cppNamespace = "::mlir::cir";
+  let cppNamespace = "::cir";
 
   let useDefaultAttributePrinterParser = 0;
   let useDefaultTypePrinterParser = 0;
@@ -31,13 +31,15 @@ def CIR_Dialect : Dialect {
     void registerAttributes();
     void registerTypes();
 
-    Type parseType(DialectAsmParser &parser) const override;
-    void printType(Type type, DialectAsmPrinter &printer) const override;
+    mlir::Type parseType(mlir::DialectAsmParser &parser) const override;
+    void printType(mlir::Type type,
+                   mlir::DialectAsmPrinter &printer) const override;
 
-    Attribute parseAttribute(DialectAsmParser &parser,
-                             Type type) const override;
+    mlir::Attribute parseAttribute(mlir::DialectAsmParser &parser,
+                                   mlir::Type type) const override;
 
-    void printAttribute(Attribute attr, DialectAsmPrinter &os) const override;
+    void printAttribute(mlir::Attribute attr,
+                        mlir::DialectAsmPrinter &os) const override;
   }];
 }
 
diff --git a/clang/include/clang/CIR/Dialect/IR/CIROps.td b/clang/include/clang/CIR/Dialect/IR/CIROps.td
index c0440faa3c7b1..4462eb6fc00ba 100644
--- a/clang/include/clang/CIR/Dialect/IR/CIROps.td
+++ b/clang/include/clang/CIR/Dialect/IR/CIROps.td
@@ -51,12 +51,12 @@ include "mlir/Interfaces/SideEffectInterfaces.td"
 // following:
 //
 //   class CIRFooOpLowering
-//       : public mlir::OpConversionPattern<mlir::cir::FooOp> {
+//       : public mlir::OpConversionPattern<cir::FooOp> {
 //   public:
-//     using OpConversionPattern<mlir::cir::FooOp>::OpConversionPattern;
+//     using OpConversionPattern<cir::FooOp>::OpConversionPattern;
 //
 //     mlir::LogicalResult matchAndRewrite(
-//         mlir::cir::FooOp op,
+//         cir::FooOp op,
 //         OpAdaptor adaptor,
 //         mlir::ConversionPatternRewriter &rewriter) const override {
 //       rewriter.replaceOpWithNewOp<mlir::LLVM::BarOp>(
@@ -92,7 +92,7 @@ def FuncOp : CIR_Op<"func"> {
 
   let skipDefaultBuilders = 1;
 
-  let builders = [OpBuilder<(ins "StringRef":$name)>];
+  let builders = [OpBuilder<(ins "llvm::StringRef":$name)>];
 
   let hasCustomAssemblyFormat = 1;
   let hasVerifier = 1;
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 5a6fc27a130c8..4e8a8cc3f4c52 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -77,7 +77,7 @@ void CIRGenModule::buildGlobal(clang::GlobalDecl gd) {
 void CIRGenModule::buildGlobalFunctionDefinition(clang::GlobalDecl gd,
                                                  mlir::Operation *op) {
   auto const *funcDecl = cast<FunctionDecl>(gd.getDecl());
-  auto funcOp = builder.create<mlir::cir::FuncOp>(
+  auto funcOp = builder.create<cir::FuncOp>(
       getLoc(funcDecl->getSourceRange()), funcDecl->getIdentifier()->getName());
   theModule.push_back(funcOp);
 }
diff --git a/clang/lib/CIR/CodeGen/CIRGenerator.cpp b/clang/lib/CIR/CodeGen/CIRGenerator.cpp
index 825f78d32e76f..85367a916ef78 100644
--- a/clang/lib/CIR/CodeGen/CIRGenerator.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenerator.cpp
@@ -35,7 +35,7 @@ void CIRGenerator::Initialize(ASTContext &astCtx) {
   this->astCtx = &astCtx;
 
   mlirCtx = std::make_unique<mlir::MLIRContext>();
-  mlirCtx->loadDialect<mlir::cir::CIRDialect>();
+  mlirCtx->loadDialect<cir::CIRDialect>();
   cgm = std::make_unique<clang::CIRGen::CIRGenModule>(*mlirCtx.get(), astCtx,
                                                       codeGenOpts, diags);
 }
diff --git a/clang/lib/CIR/Dialect/IR/CIRAttrs.cpp b/clang/lib/CIR/Dialect/IR/CIRAttrs.cpp
index 6d74d72b77dca..7d42da1ab20d7 100644
--- a/clang/lib/CIR/Dialect/IR/CIRAttrs.cpp
+++ b/clang/lib/CIR/Dialect/IR/CIRAttrs.cpp
@@ -13,7 +13,7 @@
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 
 using namespace mlir;
-using namespace mlir::cir;
+using namespace cir;
 
 //===----------------------------------------------------------------------===//
 // General CIR parsing / printing
diff --git a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
index e0b38a2902bdb..f666e5ab4b999 100644
--- a/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
+++ b/clang/lib/CIR/Dialect/IR/CIRDialect.cpp
@@ -17,13 +17,13 @@
 #include "clang/CIR/Dialect/IR/CIROpsDialect.cpp.inc"
 
 using namespace mlir;
-using namespace mlir::cir;
+using namespace cir;
 
 //===----------------------------------------------------------------------===//
 // CIR Dialect
 //===----------------------------------------------------------------------===//
 
-void mlir::cir::CIRDialect::initialize() {
+void cir::CIRDialect::initialize() {
   registerTypes();
   registerAttributes();
   addOperations<
@@ -36,8 +36,8 @@ void mlir::cir::CIRDialect::initialize() {
 // FuncOp
 //===----------------------------------------------------------------------===//
 
-void mlir::cir::FuncOp::build(OpBuilder &builder, OperationState &result,
-                              StringRef name) {
+void cir::FuncOp::build(OpBuilder &builder, OperationState &result,
+                        StringRef name) {
   result.addAttribute(SymbolTable::getSymbolAttrName(),
                       builder.getStringAttr(name));
 }
@@ -56,7 +56,7 @@ void cir::FuncOp::print(OpAsmPrinter &p) {
   p.printSymbolName(getSymName());
 }
 
-mlir::LogicalResult mlir::cir::FuncOp::verify() { return success(); }
+mlir::LogicalResult cir::FuncOp::verify() { return success(); }
 
 //===----------------------------------------------------------------------===//
 // TableGen'd op method definitions
diff --git a/clang/lib/CIR/Dialect/IR/CIRTypes.cpp b/clang/lib/CIR/Dialect/IR/CIRTypes.cpp
index 167c237ae5515..4eeb70f06f5f7 100644
--- a/clang/lib/CIR/Dialect/IR/CIRTypes.cpp
+++ b/clang/lib/CIR/Dialect/IR/CIRTypes.cpp
@@ -13,7 +13,7 @@
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 
 using namespace mlir;
-using namespace mlir::cir;
+using namespace cir;
 
 //===----------------------------------------------------------------------===//
 // General CIR parsing / printing
diff --git a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
index 60fde03289cf3..3f95a1efb2eed 100644
--- a/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ b/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -67,7 +67,7 @@ CreateFrontendBaseAction(CompilerInstance &CI) {
   case EmitBC:                 return std::make_unique<EmitBCAction>();
   case EmitCIR:
 #if CLANG_ENABLE_CIR
-    return std::make_unique<::cir::EmitCIRAction>();
+    return std::make_unique<cir::EmitCIRAction>();
 #else
     llvm_unreachable("CIR suppport not built into clang");
 #endif