diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 421ca95bb543..506af5d1458c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -15219,10 +15219,6 @@ void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
     // Add known guaranteed alignment for allocation functions.
     switch (BuiltinID) {
     case Builtin::BIaligned_alloc:
-      if (!FD->hasAttr<AllocAlignAttr>())
-        FD->addAttr(AllocAlignAttr::CreateImplicit(Context, ParamIdx(1, FD),
-                                                   FD->getLocation()));
-      LLVM_FALLTHROUGH;
     case Builtin::BIcalloc:
     case Builtin::BImalloc:
     case Builtin::BImemalign: