diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -596,11 +596,12 @@
 }
 
 static LinkageInfo getInternalLinkageFor(const NamedDecl *D) {
-  // Internal linkage declarations within a module interface unit are modeled
-  // as "module-internal linkage", which means that they have internal linkage
-  // formally but can be indirectly accessed from outside the module via inline
-  // functions and templates defined within the module.
-  if (isInModulePurview(D))
+  // (for the modules ts) Internal linkage declarations within a module
+  // interface unit are modeled as "module-internal linkage", which means that
+  // they have internal linkage formally but can be indirectly accessed from
+  // outside the module via inline functions and templates defined within the
+  // module.
+  if (isInModulePurview(D) && D->getASTContext().getLangOpts().ModulesTS)
     return LinkageInfo(ModuleInternalLinkage, DefaultVisibility, false);
 
   return LinkageInfo::internal();
diff --git a/clang/unittests/AST/DeclTest.cpp b/clang/unittests/AST/DeclTest.cpp
--- a/clang/unittests/AST/DeclTest.cpp
+++ b/clang/unittests/AST/DeclTest.cpp
@@ -194,3 +194,50 @@
   EXPECT_EQ(TemplateF->getLinkageInternal(),
             SpecializedF->getLinkageInternal());
 }
+
+TEST(Decl, ModuleAndInternalLinkage) {
+  llvm::Annotations Code(R"(
+    export module M;
+    static int a;
+    static int f(int x);
+
+    int b;
+    int g(int x);)");
+
+  auto AST =
+      tooling::buildASTFromCodeWithArgs(Code.code(), /*Args=*/{"-std=c++20"});
+  ASTContext &Ctx = AST->getASTContext();
+
+  const auto *a =
+      selectFirst<VarDecl>("a", match(varDecl(hasName("a")).bind("a"), Ctx));
+  const auto *f = selectFirst<FunctionDecl>(
+      "f", match(functionDecl(hasName("f")).bind("f"), Ctx));
+
+  EXPECT_EQ(a->getLinkageInternal(), InternalLinkage);
+  EXPECT_EQ(f->getLinkageInternal(), InternalLinkage);
+
+  const auto *b =
+      selectFirst<VarDecl>("b", match(varDecl(hasName("b")).bind("b"), Ctx));
+  const auto *g = selectFirst<FunctionDecl>(
+      "g", match(functionDecl(hasName("g")).bind("g"), Ctx));
+
+  EXPECT_EQ(b->getLinkageInternal(), ModuleLinkage);
+  EXPECT_EQ(g->getLinkageInternal(), ModuleLinkage);
+
+  AST = tooling::buildASTFromCodeWithArgs(
+      Code.code(), /*Args=*/{"-std=c++20", "-fmodules-ts"});
+  ASTContext &CtxTS = AST->getASTContext();
+  a = selectFirst<VarDecl>("a", match(varDecl(hasName("a")).bind("a"), CtxTS));
+  f = selectFirst<FunctionDecl>(
+      "f", match(functionDecl(hasName("f")).bind("f"), CtxTS));
+
+  EXPECT_EQ(a->getLinkageInternal(), ModuleInternalLinkage);
+  EXPECT_EQ(f->getLinkageInternal(), ModuleInternalLinkage);
+
+  b = selectFirst<VarDecl>("b", match(varDecl(hasName("b")).bind("b"), CtxTS));
+  g = selectFirst<FunctionDecl>(
+      "g", match(functionDecl(hasName("g")).bind("g"), CtxTS));
+
+  EXPECT_EQ(b->getLinkageInternal(), ModuleLinkage);
+  EXPECT_EQ(g->getLinkageInternal(), ModuleLinkage);
+}