diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -4018,6 +4018,7 @@
                               D->getStorageClass()))
     return ToVar;
 
+  ToVar->setTSCSpec(D->getTSCSpec());
   ToVar->setQualifierInfo(ToQualifierLoc);
   ToVar->setAccess(D->getAccess());
   ToVar->setLexicalDeclContext(LexicalDC);
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -735,6 +735,12 @@
                  has(declStmt(hasSingleDecl(varDecl(hasName("d")))))))));
 }
 
+TEST_P(ImportDecl, ImportedVarDeclPreservesThreadLocalStorage) {
+  MatchVerifier<Decl> Verifier;
+  testImport("thread_local int declToImport;", Lang_CXX11, "", Lang_CXX11,
+             Verifier, varDecl(hasThreadStorageDuration()));
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase, ImportRecordTypeInFunc) {
   Decl *FromTU = getTuDecl("int declToImport() { "
                            "  struct data_t {int a;int b;};"