diff --git a/native/IdeaWin32/CMakeLists.txt b/native/IdeaWin32/CMakeLists.txt
index 6c176c9171a6..9051e9f3b784 100644
--- a/native/IdeaWin32/CMakeLists.txt
+++ b/native/IdeaWin32/CMakeLists.txt
@@ -5,8 +5,13 @@ if(NOT WIN32)
   message(FATAL_ERROR "Windows only.")
 endif()
 
-set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+if (DEFINED ENV{BUILD_NUMBER})
+  set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+else()
+  set(BUILD_NUMBER 9999)
+endif()
 string(TIMESTAMP YEAR "%Y")
+
 if(CMAKE_GENERATOR_PLATFORM STREQUAL "x64")
   set(FILE_NAME "IdeaWin64")
   set(JAVA_HOME $ENV{JDK_18_x64})
diff --git a/native/WinFsNotifier/CMakeLists.txt b/native/WinFsNotifier/CMakeLists.txt
index f9af42e678a7..c2bd75459e45 100644
--- a/native/WinFsNotifier/CMakeLists.txt
+++ b/native/WinFsNotifier/CMakeLists.txt
@@ -5,7 +5,11 @@ if(NOT WIN32)
   message(FATAL_ERROR "Windows only.")
 endif()
 
-set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+if (DEFINED ENV{BUILD_NUMBER})
+  set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+else()
+  set(BUILD_NUMBER 9999)
+endif()
 string(TIMESTAMP YEAR "%Y")
 if(CMAKE_GENERATOR_PLATFORM STREQUAL "x64")
   set(FILE_NAME "fsnotifier64")
diff --git a/native/WinRestarter/CMakeLists.txt b/native/WinRestarter/CMakeLists.txt
index 79d95050eeeb..dcfc0fc216ae 100644
--- a/native/WinRestarter/CMakeLists.txt
+++ b/native/WinRestarter/CMakeLists.txt
@@ -5,7 +5,11 @@ if(NOT WIN32)
   message(FATAL_ERROR "Windows only.")
 endif()
 
-set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+if (DEFINED ENV{BUILD_NUMBER})
+  set(BUILD_NUMBER $ENV{BUILD_NUMBER})
+else()
+  set(BUILD_NUMBER 9999)
+endif()
 string(TIMESTAMP YEAR "%Y")
 
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} /MT")