diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 26b717439e832..7447755ef2df2 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -7115,14 +7115,6 @@ class Sema final {
                                          unsigned LambdaDependencyKind,
                                          LambdaCaptureDefault CaptureDefault);
 
-  /// Start the definition of a lambda expression.
-  CXXMethodDecl *
-  startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange,
-                        TypeSourceInfo *MethodType, SourceLocation EndLoc,
-                        ArrayRef<ParmVarDecl *> Params,
-                        ConstexprSpecKind ConstexprKind, StorageClass SC,
-                        Expr *TrailingRequiresClause);
-
   /// Number lambda for linkage purposes if necessary.
   void handleLambdaNumbering(CXXRecordDecl *Class, CXXMethodDecl *Method,
                              std::optional<CXXRecordDecl::LambdaNumbering>