diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4b5717d8..b754b2a48 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 Change Log
 ==========================
 
+4.0.6 (unreleased)
+--------------------------
+
+
+
+
 4.0.5 (463)
 --------------------------
 
diff --git a/CotEditor/CotEditor.xcodeproj/project.pbxproj b/CotEditor/CotEditor.xcodeproj/project.pbxproj
index 506359087..09db7bd7e 100644
--- a/CotEditor/CotEditor.xcodeproj/project.pbxproj
+++ b/CotEditor/CotEditor.xcodeproj/project.pbxproj
@@ -4130,10 +4130,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 463;
+				CURRENT_PROJECT_VERSION = 464;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = Info.plist;
-				MARKETING_VERSION = 4.0.5;
+				MARKETING_VERSION = "4.0.6-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.coteditor.$(PRODUCT_NAME)";
 				PRODUCT_NAME = CotEditor;
 			};
@@ -4145,10 +4145,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 463;
+				CURRENT_PROJECT_VERSION = 464;
 				ENABLE_HARDENED_RUNTIME = YES;
 				INFOPLIST_FILE = Info.plist;
-				MARKETING_VERSION = 4.0.5;
+				MARKETING_VERSION = "4.0.6-alpha";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.coteditor.$(PRODUCT_NAME)";
 				PRODUCT_NAME = CotEditor;
 			};
@@ -4212,14 +4212,14 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 463;
+				CURRENT_PROJECT_VERSION = 464;
 				ENABLE_HARDENED_RUNTIME = YES;
 				FRAMEWORK_SEARCH_PATHS = (
 					"$(inherited)",
 					"$(PROJECT_DIR)/../Frameworks/Build",
 				);
 				INFOPLIST_FILE = Info.plist;
-				MARKETING_VERSION = 4.0.5;
+				MARKETING_VERSION = "4.0.6-alpha";
 				OTHER_SWIFT_FLAGS = "$(inherited) -D SPARKLE";
 				PRODUCT_BUNDLE_IDENTIFIER = com.coteditor.CotEditor;
 				PRODUCT_NAME = CotEditor;
@@ -4232,14 +4232,14 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = "Accent Color";
-				CURRENT_PROJECT_VERSION = 463;
+				CURRENT_PROJECT_VERSION = 464;
 				ENABLE_HARDENED_RUNTIME = YES;
 				FRAMEWORK_SEARCH_PATHS = (
 					"$(inherited)",
 					"$(PROJECT_DIR)/../Frameworks/Build",
 				);
 				INFOPLIST_FILE = Info.plist;
-				MARKETING_VERSION = 4.0.5;
+				MARKETING_VERSION = "4.0.6-alpha";
 				OTHER_SWIFT_FLAGS = "$(inherited) -D SPARKLE";
 				PRODUCT_BUNDLE_IDENTIFIER = com.coteditor.CotEditor;
 				PRODUCT_NAME = CotEditor;