diff --git a/Source/cmFileLock.cxx b/Source/cmFileLock.cxx
index 5d197d2fbb..548e3279b0 100644
--- a/Source/cmFileLock.cxx
+++ b/Source/cmFileLock.cxx
@@ -12,11 +12,7 @@
 cmFileLock::cmFileLock(cmFileLock&& other) noexcept
 {
   this->File = other.File;
-#if defined(_WIN32)
-  other.File = INVALID_HANDLE_VALUE;
-#else
-  other.File = -1;
-#endif
+  other.File = (decltype(other.File))-1;
   this->Filename = std::move(other.Filename);
 }
 
@@ -32,11 +28,7 @@ cmFileLock::~cmFileLock()
 cmFileLock& cmFileLock::operator=(cmFileLock&& other) noexcept
 {
   this->File = other.File;
-#if defined(_WIN32)
-  other.File = INVALID_HANDLE_VALUE;
-#else
-  other.File = -1;
-#endif
+  other.File = (decltype(other.File))-1;
   this->Filename = std::move(other.Filename);
 
   return *this;
diff --git a/Source/cmFileLockResult.cxx b/Source/cmFileLockResult.cxx
index b7f7f38b24..632c0e9a96 100644
--- a/Source/cmFileLockResult.cxx
+++ b/Source/cmFileLockResult.cxx
@@ -5,6 +5,10 @@
 #include <cerrno>
 #include <cstring>
 
+#ifdef _WIN32
+#  include <Windows.h>
+#endif
+
 cmFileLockResult cmFileLockResult::MakeOk()
 {
   return { OK, 0 };
diff --git a/Source/cmFileLockResult.h b/Source/cmFileLockResult.h
index 8a58d1f0a3..e252de7394 100644
--- a/Source/cmFileLockResult.h
+++ b/Source/cmFileLockResult.h
@@ -6,10 +6,6 @@
 
 #include <string>
 
-#if defined(_WIN32)
-#  include <windows.h> // DWORD
-#endif
-
 /**
  * @brief Result of the locking/unlocking file.
  * @note See @c cmFileLock
@@ -17,11 +13,7 @@
 class cmFileLockResult
 {
 public:
-#if defined(_WIN32)
-  using Error = DWORD;
-#else
   using Error = int;
-#endif
 
   /**
    * @brief Successful lock/unlock.