diff --git a/clang/include/clang/Basic/DiagnosticSerializationKinds.td b/clang/include/clang/Basic/DiagnosticSerializationKinds.td
index 7965da593f218..93e31c8155ffc 100644
--- a/clang/include/clang/Basic/DiagnosticSerializationKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSerializationKinds.td
@@ -24,8 +24,9 @@ def err_fe_ast_file_modified : Error<
     DefaultFatal;
 def err_fe_pch_file_overridden : Error<
     "file '%0' from the precompiled header has been overridden">;
-def note_pch_required_by : Note<"'%0' required by '%1'">;
-def note_pch_rebuild_required : Note<"please rebuild precompiled header '%0'">;
+def note_ast_file_required_by : Note<"'%0' required by '%1'">;
+def note_ast_file_rebuild_required
+    : Note<"please rebuild precompiled file '%0'">;
 def note_module_cache_path : Note<
     "after modifying system headers, please delete the module cache at '%0'">;
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 8d2f105b2dec3..521d8f88d19de 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2862,25 +2862,25 @@ InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
       while (!ImportStack.back()->ImportedBy.empty())
         ImportStack.push_back(ImportStack.back()->ImportedBy[0]);
 
-      // The top-level PCH is stale.
-      StringRef TopLevelPCHName(ImportStack.back()->FileName);
+      // The top-level AST file is stale.
+      StringRef TopLevelASTFileName(ImportStack.back()->FileName);
       Diag(diag::err_fe_ast_file_modified)
           << *Filename << moduleKindForDiagnostic(ImportStack.back()->Kind)
-          << TopLevelPCHName << FileChange.Kind
+          << TopLevelASTFileName << FileChange.Kind
           << (FileChange.Old && FileChange.New)
           << llvm::itostr(FileChange.Old.value_or(0))
           << llvm::itostr(FileChange.New.value_or(0));
 
       // Print the import stack.
       if (ImportStack.size() > 1) {
-        Diag(diag::note_pch_required_by)
+        Diag(diag::note_ast_file_required_by)
             << *Filename << ImportStack[0]->FileName;
         for (unsigned I = 1; I < ImportStack.size(); ++I)
-          Diag(diag::note_pch_required_by)
-            << ImportStack[I-1]->FileName << ImportStack[I]->FileName;
+          Diag(diag::note_ast_file_required_by)
+              << ImportStack[I - 1]->FileName << ImportStack[I]->FileName;
       }
 
-      Diag(diag::note_pch_rebuild_required) << TopLevelPCHName;
+      Diag(diag::note_ast_file_rebuild_required) << TopLevelASTFileName;
     }
 
     IsOutOfDate = true;
diff --git a/clang/test/Modules/module-file-modified.c b/clang/test/Modules/module-file-modified.c
index 85018b521e288..57160f34a46cf 100644
--- a/clang/test/Modules/module-file-modified.c
+++ b/clang/test/Modules/module-file-modified.c
@@ -8,4 +8,5 @@
 #include "a.h"
 int foo = 0; // redefinition of 'foo'
 // CHECK: fatal error: file {{.*}} has been modified since the module file {{.*}} was built
+// CHECK: note: please rebuild precompiled file
 // REQUIRES: shell
diff --git a/clang/test/Modules/validate-file-content.m b/clang/test/Modules/validate-file-content.m
index 327a68a9b641e..9977aa4665f04 100644
--- a/clang/test/Modules/validate-file-content.m
+++ b/clang/test/Modules/validate-file-content.m
@@ -29,5 +29,5 @@
 // CHECK: file '[[M_H:.*[/\\]m\.h]]' has been modified since the precompiled header '[[A_PCH:.*/a\.pch]]' was built: content changed
 // CHECK: '[[M_H]]' required by '[[M_PCM:.*[/\\]m.*\.pcm]]'
 // CHECK: '[[M_PCM]]' required by '[[A_PCH]]'
-// CHECK: please rebuild precompiled header '[[A_PCH]]'
+// CHECK: please rebuild precompiled file '[[A_PCH]]'
 // expected-no-diagnostics
diff --git a/clang/test/PCH/modified-module-dependency.m b/clang/test/PCH/modified-module-dependency.m
index 44c14b3a0231c..a4710dea51169 100644
--- a/clang/test/PCH/modified-module-dependency.m
+++ b/clang/test/PCH/modified-module-dependency.m
@@ -17,4 +17,4 @@
 // CHECK: file '[[TEST_H:.*[/\\]test\.h]]' has been modified since the precompiled header '[[PREFIX_PCH:.*/prefix\.pch]]' was built
 // CHECK: '[[TEST_H]]' required by '[[TEST_PCM:.*[/\\]test\.pcm]]'
 // CHECK: '[[TEST_PCM]]' required by '[[PREFIX_PCH]]'
-// CHECK: please rebuild precompiled header '[[PREFIX_PCH]]'
+// CHECK: please rebuild precompiled file '[[PREFIX_PCH]]'
diff --git a/clang/test/PCH/validate-file-content.m b/clang/test/PCH/validate-file-content.m
index aba4944a28e91..b98979341b76a 100644
--- a/clang/test/PCH/validate-file-content.m
+++ b/clang/test/PCH/validate-file-content.m
@@ -25,5 +25,5 @@
 // RUN: FileCheck %s < %t/stderr
 //
 // CHECK: file '[[M_H:.*[/\\]m\.h]]' has been modified since the precompiled header '[[A_PCH:.*/a\.pch]]' was built: content changed
-// CHECK: please rebuild precompiled header '[[A_PCH]]'
+// CHECK: please rebuild precompiled file '[[A_PCH]]'
 // expected-no-diagnostics