diff --git a/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp b/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
--- a/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
+++ b/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
@@ -61,7 +61,9 @@
   if (auto *Node = Inputs.ASTSelection.commonAncestor()) {
     if (auto *TypeNode = Node->ASTNode.get<TypeLoc>()) {
       if (const AutoTypeLoc Result = TypeNode->getAs<AutoTypeLoc>()) {
-        CachedLocation = Result;
+        // Code in apply() does handle 'decltype(auto)' yet.
+        if (!Result.getTypePtr()->isDecltypeAuto())
+          CachedLocation = Result;
       }
     }
   }
diff --git a/clang-tools-extra/clangd/unittests/TweakTests.cpp b/clang-tools-extra/clangd/unittests/TweakTests.cpp
--- a/clang-tools-extra/clangd/unittests/TweakTests.cpp
+++ b/clang-tools-extra/clangd/unittests/TweakTests.cpp
@@ -528,6 +528,8 @@
   // replace array types
   EXPECT_EQ(apply(R"cpp(au^to x = "test")cpp"),
             R"cpp(const char * x = "test")cpp");
+
+  EXPECT_UNAVAILABLE("dec^ltype(au^to) x = 10;");
 }
 
 TWEAK_TEST(ExtractFunction);