diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9303f26cb..89fe58043 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 Change Log
 ==========================
 
+4.2.1 (unreleased)
+--------------------------
+
+
+
 4.2.0 (502)
 --------------------------
 
diff --git a/CotEditor.xcodeproj/project.pbxproj b/CotEditor.xcodeproj/project.pbxproj
index d0158942d..f5bf3caeb 100644
--- a/CotEditor.xcodeproj/project.pbxproj
+++ b/CotEditor.xcodeproj/project.pbxproj
@@ -4378,10 +4378,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 502;
+				CURRENT_PROJECT_VERSION = 503;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = CotEditor/Info.plist;
-				MARKETING_VERSION = 4.2.0;
+				MARKETING_VERSION = "4.2.1-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.coteditor.$(PRODUCT_NAME)";
 				PRODUCT_NAME = CotEditor;
 			};
@@ -4393,10 +4393,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 502;
+				CURRENT_PROJECT_VERSION = 503;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = CotEditor/Info.plist;
-				MARKETING_VERSION = 4.2.0;
+				MARKETING_VERSION = "4.2.1-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.coteditor.$(PRODUCT_NAME)";
 				PRODUCT_NAME = CotEditor;
 			};
@@ -4432,10 +4432,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 502;
+				CURRENT_PROJECT_VERSION = 503;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = CotEditor/Info.plist;
-				MARKETING_VERSION = 4.2.0;
+				MARKETING_VERSION = "4.2.1-alpha";
 				OTHER_SWIFT_FLAGS = "$(inherited) -D SPARKLE";
 				PRODUCT_BUNDLE_IDENTIFIER = com.coteditor.CotEditor;
 				PRODUCT_NAME = CotEditor;
@@ -4448,10 +4448,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 502;
+				CURRENT_PROJECT_VERSION = 503;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = CotEditor/Info.plist;
-				MARKETING_VERSION = 4.2.0;
+				MARKETING_VERSION = "4.2.1-alpha";
 				OTHER_SWIFT_FLAGS = "$(inherited) -D SPARKLE";
 				PRODUCT_BUNDLE_IDENTIFIER = com.coteditor.CotEditor;
 				PRODUCT_NAME = CotEditor;