diff --git a/clang/lib/Sema/HLSLExternalSemaSource.cpp b/clang/lib/Sema/HLSLExternalSemaSource.cpp
index ee3aa4d42a04..969d65997cdc 100644
--- a/clang/lib/Sema/HLSLExternalSemaSource.cpp
+++ b/clang/lib/Sema/HLSLExternalSemaSource.cpp
@@ -270,6 +270,9 @@ struct BuiltinTypeDeclBuilder {
                                              SourceLocation()));
     MethodDecl->setLexicalDeclContext(Record);
     MethodDecl->setAccess(AccessSpecifier::AS_public);
+    MethodDecl->addAttr(AlwaysInlineAttr::CreateImplicit(
+        AST, SourceRange(), AttributeCommonInfo::AS_Keyword,
+        AlwaysInlineAttr::CXX11_clang_always_inline));
     Record->addDecl(MethodDecl);
 
     return *this;
diff --git a/clang/test/AST/HLSL/RWBuffer-AST.hlsl b/clang/test/AST/HLSL/RWBuffer-AST.hlsl
index 193ef67e152b..80f77f97d2ef 100644
--- a/clang/test/AST/HLSL/RWBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/RWBuffer-AST.hlsl
@@ -49,6 +49,7 @@ RWBuffer<float> Buffer;
 // CHECK-NEXT: MemberExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'element_type *' lvalue ->h 0x{{[0-9A-Fa-f]+}}
 // CHECK-NEXT: CXXThisExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'const RWBuffer<element_type> *' implicit this
 // CHECK-NEXT: DeclRefExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'unsigned int' ParmVar 0x{{[0-9A-Fa-f]+}} 'Idx' 'unsigned int'
+// CHECK-NEXT: AlwaysInlineAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit always_inline
 
 // CHECK-NEXT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &(unsigned int)'
 // CHECK-NEXT: ParmVarDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> Idx 'unsigned int'
@@ -58,6 +59,7 @@ RWBuffer<float> Buffer;
 // CHECK-NEXT: MemberExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'element_type *' lvalue ->h 0x{{[0-9A-Fa-f]+}}
 // CHECK-NEXT: CXXThisExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'RWBuffer<element_type> *' implicit this
 // CHECK-NEXT: DeclRefExpr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> 'unsigned int' ParmVar 0x{{[0-9A-Fa-f]+}} 'Idx' 'unsigned int'
+// CHECK-NEXT: AlwaysInlineAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit always_inline
 
 // CHECK: ClassTemplateSpecializationDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> class RWBuffer definition