diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 1e00b41cd8149..8ba7fa2479d04 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -3707,6 +3707,21 @@ QualType ASTContext::mergeBoundsSafetyPointerTypes(
   if (OrigDstTy.isNull())
     OrigDstTy = DstTy;
 
+  // An ugly way to keep va_list typedef in DstTy if the merge type doesn't
+  // change.
+  // TODO: We need a general way of not stripping sugars.
+  QualType DesugaredDstTy;
+  if (const auto *TDT = dyn_cast<TypedefType>(DstTy))
+    DesugaredDstTy = TDT->desugar();
+  else if (const auto *ET = dyn_cast<ElaboratedType>(DstTy))
+    DesugaredDstTy = ET->desugar();
+  if (!DesugaredDstTy.isNull()) {
+    QualType MergeTy = mergeBoundsSafetyPointerTypes(DesugaredDstTy, SrcTy,
+                                                     MergeFunctor, OrigDstTy);
+    if (MergeTy == DesugaredDstTy)
+      return DstTy;
+  }
+
   // FIXME: a brittle hack to avoid skipping ValueTerminatedType outside
   // this PtrAutoAttr AttributedType.
   bool RecoverPtrAuto = false;
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ca34eaee9ada7..22ecaace79d64 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -4040,33 +4040,12 @@ static bool mergeFunctionDeclBoundsAttributes(FunctionDecl *New,
     }
     return MergeTy;
   };
-
-  auto hasBoundsAttributesAtAnyLevel = [](QualType Ty) -> bool {
-    while (Ty->isPointerType()) {
-      if (!Ty->isUnspecifiedPointerType())
-        return true;
-      Ty = Ty->getPointeeType();
-    }
-    return false;
-  };
-
-  auto mergePointersWithAttributes = [&](QualType NewTy,
-                                         QualType OldTy) -> QualType {
-    // Do not attempt to merge if there is no need to do so. This will let us
-    // keep the sugars used in the new declaration.
-    if (!hasBoundsAttributesAtAnyLevel(NewTy) &&
-        !hasBoundsAttributesAtAnyLevel(OldTy))
-      return NewTy;
-    return Self.Context.mergeBoundsSafetyPointerTypes(NewTy, OldTy,
-                                                      mergeBoundsAttributes);
-  };
-
   QualType NewRetTy = New->getReturnType();
   if (NewRetTy->isBoundsAttributedType() ||
       NewRetTy->isValueTerminatedType())
     return false;
-  QualType MergeRetTy =
-      mergePointersWithAttributes(New->getReturnType(), Old->getReturnType());
+  QualType MergeRetTy = Self.Context.mergeBoundsSafetyPointerTypes(
+      New->getReturnType(), Old->getReturnType(), mergeBoundsAttributes);
   if (MergeRetTy.isNull())
     return false;
 
@@ -4076,8 +4055,9 @@ static bool mergeFunctionDeclBoundsAttributes(FunctionDecl *New,
     if (NewParmTy->isBoundsAttributedType() ||
         NewParmTy->isValueTerminatedType())
       return false;
-    QualType MergeParamTy =
-        mergePointersWithAttributes(NewParmTy, Old->getParamDecl(i)->getType());
+    QualType MergeParamTy = Self.Context.mergeBoundsSafetyPointerTypes(
+        NewParmTy, Old->getParamDecl(i)->getType(),
+        mergeBoundsAttributes);
     if (MergeParamTy.isNull())
       return false;
     if (const auto *CATy = MergeParamTy->getAs<CountAttributedType>()) {
diff --git a/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.c b/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.c
index 3e9adc3bde2ff..eed32ffe1f8aa 100644
--- a/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.c
+++ b/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.c
@@ -29,9 +29,6 @@
 // CHECK: FunctionDecl {{.+}} eb
 // CHECK: |-ParmVarDecl {{.+}} eb_p 'void *'
 // CHECK: `-ParmVarDecl {{.+}} end 'void *'
-// CHECK: FunctionDecl {{.+}} cb_array
-// CHECK: |-ParmVarDecl {{.+}} array 'int *'
-// CHECK: `-ParmVarDecl {{.+}} len 'int'
 
 
 // Check if we can override them.
@@ -42,7 +39,6 @@ void cb_out_count(int *__counted_by(*len) cb_out_len_p, int *len);
 void cbn(int *__counted_by_or_null(len) cbn_p, int len);
 void sb(void *__sized_by(size) sb_p, int size);
 void eb(void *__ended_by(end) eb_p, void *end);
-void cb_array(int array[__counted_by(len)], int len);
 
 // CHECK: FunctionDecl {{.+}} prev {{.+}} cb_in
 // CHECK: |-ParmVarDecl {{.+}} cb_in_p 'int *{{.*}} __counted_by(len)'
@@ -62,9 +58,6 @@ void cb_array(int array[__counted_by(len)], int len);
 // CHECK: FunctionDecl {{.+}} prev {{.+}} eb
 // CHECK: |-ParmVarDecl {{.+}} used eb_p 'void *{{.*}} __ended_by(end)'
 // CHECK: `-ParmVarDecl {{.+}} used end 'void *{{.*}} /* __started_by(eb_p) */ '
-// CHECK: FunctionDecl {{.+}} prev {{.+}} cb_array
-// CHECK: |-ParmVarDecl {{.+}} array 'int *{{.*}} __counted_by(len)'
-// CHECK: `-ParmVarDecl {{.+}} used len 'int'
 
 
 // Check if the attributes are merged.
@@ -89,6 +82,3 @@ void cb_array(int array[__counted_by(len)], int len);
 // CHECK: FunctionDecl {{.+}} prev {{.+}} eb
 // CHECK: |-ParmVarDecl {{.+}} used eb_p 'void *{{.*}} __ended_by(end)'
 // CHECK: `-ParmVarDecl {{.+}} used end 'void *{{.*}} /* __started_by(eb_p) */ '
-// CHECK: FunctionDecl {{.+}} prev {{.+}} cb_array
-// CHECK: |-ParmVarDecl {{.+}} array 'int *{{.*}} __counted_by(len)'
-// CHECK: `-ParmVarDecl {{.+}} used len 'int'
diff --git a/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.h b/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.h
index abef43f41a6f0..b3d0fcb78790e 100644
--- a/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.h
+++ b/clang/test/BoundsSafety/AST/system-header-merge-bounds-attributed.h
@@ -6,4 +6,3 @@ void cb_out_count(int *cb_out_len_p, int *len);
 void cbn(int *cbn_p, int len);
 void sb(void *sb_p, int size);
 void eb(void *eb_p, void *end);
-void cb_array(int array[], int len);