diff --git a/clang/include/clang/Serialization/ModuleFile.h b/clang/include/clang/Serialization/ModuleFile.h
index 871fdd0a48381..45fb75df8a435 100644
--- a/clang/include/clang/Serialization/ModuleFile.h
+++ b/clang/include/clang/Serialization/ModuleFile.h
@@ -164,6 +164,9 @@ class ModuleFile {
   /// Whether this precompiled header is a relocatable PCH file.
   bool RelocatablePCH = false;
 
+  /// Whether this mdoule file is a standard c++ module.
+  bool StandardCXXModule = false;
+
   /// Whether timestamps are included in this module file.
   bool HasTimestamps = false;
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 13fec49e841cc..9c31f9db14679 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2389,12 +2389,15 @@ InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
   StringRef Filename = FI.Filename;
   uint64_t StoredContentHash = FI.ContentHash;
 
+  // For standard C++ modules, we don't need to check the inputs.
+  bool SkipChecks = F.StandardCXXModule;
+
   OptionalFileEntryRefDegradesToFileEntryPtr File = OptionalFileEntryRef(
       expectedToOptional(FileMgr.getFileRef(Filename, /*OpenFile=*/false)));
 
   // For an overridden file, create a virtual file with the stored
   // size/timestamp.
-  if ((Overridden || Transient) && !File)
+  if ((Overridden || Transient || SkipChecks) && !File)
     File = FileMgr.getVirtualFileRef(Filename, StoredSize, StoredTime);
 
   if (!File) {
@@ -2417,7 +2420,7 @@ InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
   // PCH.
   SourceManager &SM = getSourceManager();
   // FIXME: Reject if the overrides are different.
-  if ((!Overridden && !Transient) && SM.isFileOverridden(File)) {
+  if ((!Overridden && !Transient) && !SkipChecks && SM.isFileOverridden(File)) {
     if (Complain)
       Error(diag::err_fe_pch_file_overridden, Filename);
 
@@ -2476,7 +2479,7 @@ InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
   };
 
   bool IsOutOfDate = false;
-  auto FileChange = HasInputFileChanged();
+  auto FileChange = SkipChecks ? Change{Change::None} : HasInputFileChanged();
   // For an overridden file, there is nothing to validate.
   if (!Overridden && FileChange.Kind != Change::None) {
     if (Complain && !Diags.isDiagnosticInFlight()) {
@@ -2821,7 +2824,7 @@ ASTReader::ReadControlBlock(ModuleFile &F,
         return VersionMismatch;
       }
 
-      bool hasErrors = Record[6];
+      bool hasErrors = Record[7];
       if (hasErrors && !DisableValidation) {
         // If requested by the caller and the module hasn't already been read
         // or compiled, mark modules on error as out-of-date.
@@ -2845,7 +2848,9 @@ ASTReader::ReadControlBlock(ModuleFile &F,
       if (F.RelocatablePCH)
         F.BaseDirectory = isysroot.empty() ? "/" : isysroot;
 
-      F.HasTimestamps = Record[5];
+      F.StandardCXXModule = Record[5];
+
+      F.HasTimestamps = Record[6];
 
       const std::string &CurBranch = getClangFullRepositoryVersion();
       StringRef ASTBranch = Blob;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 94c851d2dbf16..e124cb4c5f81d 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1243,6 +1243,8 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
+  // Standard C++ module
+  MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
@@ -1250,15 +1252,15 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
   assert((!WritingModule || isysroot.empty()) &&
          "writing module as a relocatable PCH?");
   {
-    RecordData::value_type Record[] = {
-        METADATA,
-        VERSION_MAJOR,
-        VERSION_MINOR,
-        CLANG_VERSION_MAJOR,
-        CLANG_VERSION_MINOR,
-        !isysroot.empty(),
-        IncludeTimestamps,
-        ASTHasCompilerErrors};
+    RecordData::value_type Record[] = {METADATA,
+                                       VERSION_MAJOR,
+                                       VERSION_MINOR,
+                                       CLANG_VERSION_MAJOR,
+                                       CLANG_VERSION_MINOR,
+                                       !isysroot.empty(),
+                                       isWritingStdCXXNamedModules(),
+                                       IncludeTimestamps,
+                                       ASTHasCompilerErrors};
     Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
                               getClangFullRepositoryVersion());
   }
diff --git a/clang/test/Modules/cxx20-no-check-input.cppm b/clang/test/Modules/cxx20-no-check-input.cppm
new file mode 100644
index 0000000000000..f4b42b444f2e4
--- /dev/null
+++ b/clang/test/Modules/cxx20-no-check-input.cppm
@@ -0,0 +1,56 @@
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+// RUN: cd %t
+//
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.cppm -emit-module-interface -o %t/a.pcm
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/use.cpp -fmodule-file=a=%t/a.pcm -verify -fsyntax-only
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.pcm -emit-llvm -o - | FileCheck %t/a.ll
+//
+// RUN: echo "//Update" >> %t/foo.h
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/use.cpp -fmodule-file=a=%t/a.pcm -verify -fsyntax-only
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.pcm -emit-llvm -o - | FileCheck %t/a.ll
+//
+// RUN: echo "//Update" >> %t/a.cppm
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/use.cpp -fmodule-file=a=%t/a.pcm -verify -fsyntax-only
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.pcm -emit-llvm -o - | FileCheck %t/a.ll
+//
+// RUN: rm -f %t/foo.h
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/use.cpp -fmodule-file=a=%t/a.pcm -verify -fsyntax-only
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.pcm -emit-llvm -o - | FileCheck %t/a.ll
+//
+// RUN: rm -f %t/a.cppm
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/use.cpp -fmodule-file=a=%t/a.pcm -verify -fsyntax-only
+// RUN: %clang_cc1 -std=c++20 -triple %itanium_abi_triple \
+// RUN:     %t/a.pcm -emit-llvm -o - | FileCheck %t/a.ll
+
+//--- foo.h
+inline int foo = 43;
+
+//--- a.cppm
+// expected-no-diagnostics
+module;
+#include "foo.h"
+export module a;
+export using ::foo;
+
+//--- a.ll
+// check the LLVM IR are generated succesfully.
+// CHECK: define{{.*}}@_ZGIW1a
+
+//--- use.cpp
+// expected-no-diagnostics
+import a;
+int use() {
+    return foo;
+}
+