diff --git a/clang/include/clang/Basic/DiagnosticSerializationKinds.td b/clang/include/clang/Basic/DiagnosticSerializationKinds.td
--- a/clang/include/clang/Basic/DiagnosticSerializationKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSerializationKinds.td
@@ -63,12 +63,12 @@
 
 def err_module_file_conflict : Error<
   "module '%0' is defined in both '%1' and '%2'">, DefaultFatal;
-def err_module_file_not_found : Error<
+def err_ast_file_not_found : Error<
   "%select{PCH|module|AST}0 file '%1' not found%select{|: %3}2">, DefaultFatal;
-def err_module_file_out_of_date : Error<
+def err_ast_file_out_of_date : Error<
   "%select{PCH|module|AST}0 file '%1' is out of date and "
   "needs to be rebuilt%select{|: %3}2">, DefaultFatal;
-def err_module_file_invalid : Error<
+def err_ast_file_invalid : Error<
   "file '%1' is not a valid precompiled %select{PCH|module|AST}0 file">, DefaultFatal;
 def note_module_file_imported_by : Note<
   "imported by %select{|module '%2' in }1'%0'">;
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4505,9 +4505,9 @@
       return Missing;
 
     // Otherwise, return an error.
-    Diag(diag::err_module_file_not_found) << moduleKindForDiagnostic(Type)
-                                          << FileName << !ErrorStr.empty()
-                                          << ErrorStr;
+    Diag(diag::err_ast_file_not_found)
+        << moduleKindForDiagnostic(Type) << FileName << !ErrorStr.empty()
+        << ErrorStr;
     return Failure;
 
   case ModuleManager::OutOfDate:
@@ -4517,9 +4517,9 @@
       return OutOfDate;
 
     // Otherwise, return an error.
-    Diag(diag::err_module_file_out_of_date) << moduleKindForDiagnostic(Type)
-                                            << FileName << !ErrorStr.empty()
-                                            << ErrorStr;
+    Diag(diag::err_ast_file_out_of_date)
+        << moduleKindForDiagnostic(Type) << FileName << !ErrorStr.empty()
+        << ErrorStr;
     return Failure;
   }
 
@@ -4540,7 +4540,7 @@
 
   // Sniff for the signature.
   if (llvm::Error Err = doesntStartWithASTFileMagic(Stream)) {
-    Diag(diag::err_module_file_invalid)
+    Diag(diag::err_ast_file_invalid)
         << moduleKindForDiagnostic(Type) << FileName << std::move(Err);
     return Failure;
   }