diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2885,10 +2885,16 @@
       !Args.hasArg(OPT_fno_concept_satisfaction_caching);
   if (Args.hasArg(OPT_fconcepts_ts))
     Diags.Report(diag::warn_fe_concepts_ts_flag);
+
+  // Recovery AST still heavily relies on dependent-type machinery, so C++ only
+  // for now.
   Opts.RecoveryAST =
-      Args.hasFlag(OPT_frecovery_ast, OPT_fno_recovery_ast, false);
+      Args.hasFlag(OPT_frecovery_ast, OPT_fno_recovery_ast, false) &&
+      Opts.CPlusPlus;
   Opts.RecoveryASTType =
-+      Args.hasFlag(OPT_frecovery_ast_type, OPT_fno_recovery_ast_type, false);
+      Args.hasFlag(OPT_frecovery_ast_type, OPT_fno_recovery_ast_type, false) &&
+      Opts.CPlusPlus;
+
   Opts.HeinousExtensions = Args.hasArg(OPT_fheinous_gnu_extensions);
   Opts.AccessControl = !Args.hasArg(OPT_fno_access_control);
   Opts.ElideConstructors = !Args.hasArg(OPT_fno_elide_constructors);