diff --git a/PCbuild/BUILDno.txt b/PCbuild/BUILDno.txt
index 9b364a6974f..97aca465533 100644
--- a/PCbuild/BUILDno.txt
+++ b/PCbuild/BUILDno.txt
@@ -33,6 +33,8 @@ How to change the Windows build number:
 
 Windows Python BUILD numbers
 ----------------------------
+  57    2.4.0b1
+        15-Oct-2004
   56    2.4.0a3
         2-Sep-2004
   55    2.4.0a2
diff --git a/PCbuild/pythoncore.vcproj b/PCbuild/pythoncore.vcproj
index 59bddb3b2a8..d101b4f61ad 100644
--- a/PCbuild/pythoncore.vcproj
+++ b/PCbuild/pythoncore.vcproj
@@ -1385,7 +1385,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="2"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=56"/>
+					PreprocessorDefinitions="BUILD=57"/>
 			</FileConfiguration>
 			<FileConfiguration
 				Name="Debug|Win32">
@@ -1393,7 +1393,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="0"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=56"/>
+					PreprocessorDefinitions="BUILD=57"/>
 			</FileConfiguration>
 			<FileConfiguration
 				Name="ReleaseItanium|Win32">
@@ -1401,7 +1401,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="2"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=56"/>
+					PreprocessorDefinitions="BUILD=57"/>
 			</FileConfiguration>
 		</File>
 		<File