diff --git a/src/indexer.hh b/src/indexer.hh
index 55bc1ffb..b0ea2de1 100644
--- a/src/indexer.hh
+++ b/src/indexer.hh
@@ -16,7 +16,6 @@ limitations under the License.
 #pragma once
 
 #include "lsp.hh"
-#include "maybe.hh"
 #include "position.hh"
 #include "serializer.hh"
 #include "utils.hh"
diff --git a/src/maybe.hh b/src/maybe.hh
deleted file mode 100644
index e62f2792..00000000
--- a/src/maybe.hh
+++ /dev/null
@@ -1,60 +0,0 @@
-/* Copyright 2017-2018 ccls Authors
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-  http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-==============================================================================*/
-
-#pragma once
-
-#include <optional>
-
-#include <utility>
-
-namespace ccls {
-// Like std::optional, but the stored data is responsible for containing the
-// empty state. T should define a function `bool T::Valid()`.
-template <typename T> class Maybe {
-  T storage;
-
-public:
-  constexpr Maybe() = default;
-  Maybe(const Maybe &) = default;
-  Maybe(std::nullopt_t) {}
-  Maybe(const T &x) : storage(x) {}
-  Maybe(T &&x) : storage(std::forward<T>(x)) {}
-
-  Maybe &operator=(const Maybe &) = default;
-  Maybe &operator=(const T &x) {
-    storage = x;
-    return *this;
-  }
-
-  const T *operator->() const { return &storage; }
-  T *operator->() { return &storage; }
-  const T &operator*() const { return storage; }
-  T &operator*() { return storage; }
-
-  bool Valid() const { return storage.Valid(); }
-  explicit operator bool() const { return Valid(); }
-  operator std::optional<T>() const {
-    if (Valid())
-      return storage;
-    return std::nullopt;
-  }
-
-  void operator=(std::optional<T> &&o) { storage = o ? *o : T(); }
-
-  // Does not test if has_value()
-  bool operator==(const Maybe &o) const { return storage == o.storage; }
-  bool operator!=(const Maybe &o) const { return !(*this == o); }
-};
-} // namespace ccls
diff --git a/src/position.hh b/src/position.hh
index e595e1ed..11075e90 100644
--- a/src/position.hh
+++ b/src/position.hh
@@ -15,7 +15,6 @@ limitations under the License.
 
 #pragma once
 
-#include "maybe.hh"
 #include "utils.hh"
 
 #include <stdint.h>
diff --git a/src/serializer.hh b/src/serializer.hh
index b57dbfae..dc469d30 100644
--- a/src/serializer.hh
+++ b/src/serializer.hh
@@ -15,7 +15,7 @@ limitations under the License.
 
 #pragma once
 
-#include "maybe.hh"
+#include "utils.hh"
 
 #include <llvm/Support/Compiler.h>
 
diff --git a/src/utils.hh b/src/utils.hh
index d6d07966..fcda9d8e 100644
--- a/src/utils.hh
+++ b/src/utils.hh
@@ -21,6 +21,7 @@ limitations under the License.
 #include <iterator>
 #include <memory>
 #include <string>
+#include <utility>
 #include <vector>
 
 namespace llvm {
@@ -99,4 +100,42 @@ inline void hash_combine(std::size_t &seed, const T &v, Rest... rest) {
   }
 
 std::string GetDefaultResourceDirectory();
+
+// Like std::optional, but the stored data is responsible for containing the
+// empty state. T should define a function `bool T::Valid()`.
+template <typename T> class Maybe {
+  T storage;
+
+public:
+  constexpr Maybe() = default;
+  Maybe(const Maybe &) = default;
+  Maybe(std::nullopt_t) {}
+  Maybe(const T &x) : storage(x) {}
+  Maybe(T &&x) : storage(std::forward<T>(x)) {}
+
+  Maybe &operator=(const Maybe &) = default;
+  Maybe &operator=(const T &x) {
+    storage = x;
+    return *this;
+  }
+
+  const T *operator->() const { return &storage; }
+  T *operator->() { return &storage; }
+  const T &operator*() const { return storage; }
+  T &operator*() { return storage; }
+
+  bool Valid() const { return storage.Valid(); }
+  explicit operator bool() const { return Valid(); }
+  operator std::optional<T>() const {
+    if (Valid())
+      return storage;
+    return std::nullopt;
+  }
+
+  void operator=(std::optional<T> &&o) { storage = o ? *o : T(); }
+
+  // Does not test if has_value()
+  bool operator==(const Maybe &o) const { return storage == o.storage; }
+  bool operator!=(const Maybe &o) const { return !(*this == o); }
+};
 } // namespace ccls