diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,7 @@ if(NOT BINARY_NAME)
 endif()
 
 project(${BINARY_NAME}
-    VERSION 14.0
+    VERSION 15.0
     LANGUAGES CXX
 )
 
diff --git a/bin/ai/CMakeLists.txt b/bin/ai/CMakeLists.txt
--- a/bin/ai/CMakeLists.txt
+++ b/bin/ai/CMakeLists.txt
@@ -15,6 +15,7 @@ set(AI_COMPAT_SOURCE_FILES
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_12.nut
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_13.nut
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_14.nut
+	${CMAKE_CURRENT_SOURCE_DIR}/compat_15.nut
 )
 
 foreach(AI_COMPAT_SOURCE_FILE IN LISTS AI_COMPAT_SOURCE_FILES)
diff --git a/bin/ai/compat_14.nut b/bin/ai/compat_14.nut
--- a/bin/ai/compat_14.nut
+++ b/bin/ai/compat_14.nut
@@ -4,3 +4,5 @@
  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
  */
+
+AILog.Info("14 API compatibility in effect.");
diff --git a/bin/ai/compat_15.nut b/bin/ai/compat_15.nut
new file mode 100644
--- /dev/null
+++ b/bin/ai/compat_15.nut
@@ -0,0 +1,6 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
diff --git a/bin/game/CMakeLists.txt b/bin/game/CMakeLists.txt
--- a/bin/game/CMakeLists.txt
+++ b/bin/game/CMakeLists.txt
@@ -12,6 +12,7 @@ set(GS_COMPAT_SOURCE_FILES
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_12.nut
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_13.nut
 	${CMAKE_CURRENT_SOURCE_DIR}/compat_14.nut
+	${CMAKE_CURRENT_SOURCE_DIR}/compat_15.nut
 )
 
 foreach(GS_COMPAT_SOURCE_FILE IN LISTS GS_COMPAT_SOURCE_FILES)
diff --git a/bin/game/compat_14.nut b/bin/game/compat_14.nut
--- a/bin/game/compat_14.nut
+++ b/bin/game/compat_14.nut
@@ -4,3 +4,5 @@
  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
  */
+
+GSLog.Info("14 API compatibility in effect.");
diff --git a/bin/game/compat_15.nut b/bin/game/compat_15.nut
new file mode 100644
--- /dev/null
+++ b/bin/game/compat_15.nut
@@ -0,0 +1,6 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
diff --git a/regression/regression/info.nut b/regression/regression/info.nut
--- a/regression/regression/info.nut
+++ b/regression/regression/info.nut
@@ -4,7 +4,7 @@ class Regression extends AIInfo {
 	function GetShortName()   { return "REGR"; }
 	function GetDescription() { return "This runs regression-tests on some commands. On the same map the result should always be the same."; }
 	function GetVersion()     { return 1; }
-	function GetAPIVersion()  { return "14"; }
+	function GetAPIVersion()  { return "15"; }
 	function GetDate()        { return "2007-03-18"; }
 	function CreateInstance() { return "Regression"; }
 	function UseAsRandomAI()  { return false; }
diff --git a/regression/stationlist/info.nut b/regression/stationlist/info.nut
--- a/regression/stationlist/info.nut
+++ b/regression/stationlist/info.nut
@@ -4,7 +4,7 @@ class StationList extends AIInfo {
 	function GetShortName()   { return "REGS"; }
 	function GetDescription() { return "This runs stationlist-tests on some commands. On the same map the result should always be the same."; }
 	function GetVersion()     { return 1; }
-	function GetAPIVersion()  { return "14"; }
+	function GetAPIVersion()  { return "15"; }
 	function GetDate()        { return "2007-03-18"; }
 	function CreateInstance() { return "StationList"; }
 	function UseAsRandomAI()  { return false; }
diff --git a/src/ai/ai_info.cpp b/src/ai/ai_info.cpp
--- a/src/ai/ai_info.cpp
+++ b/src/ai/ai_info.cpp
@@ -24,7 +24,7 @@
  */
 static bool CheckAPIVersion(const std::string &api_version)
 {
-	static const std::set<std::string> versions = { "0.7", "1.0", "1.1", "1.2", "1.3", "1.4", "1.5", "1.6", "1.7", "1.8", "1.9", "1.10", "1.11", "12", "13", "14" };
+	static const std::set<std::string> versions = { "0.7", "1.0", "1.1", "1.2", "1.3", "1.4", "1.5", "1.6", "1.7", "1.8", "1.9", "1.10", "1.11", "12", "13", "14", "15" };
 	return versions.find(api_version) != versions.end();
 }
 
diff --git a/src/game/game_info.cpp b/src/game/game_info.cpp
--- a/src/game/game_info.cpp
+++ b/src/game/game_info.cpp
@@ -22,7 +22,7 @@
  */
 static bool CheckAPIVersion(const std::string &api_version)
 {
-	static const std::set<std::string> versions = { "1.2", "1.3", "1.4", "1.5", "1.6", "1.7", "1.8", "1.9", "1.10", "1.11", "12", "13", "14" };
+	static const std::set<std::string> versions = { "1.2", "1.3", "1.4", "1.5", "1.6", "1.7", "1.8", "1.9", "1.10", "1.11", "12", "13", "14", "15" };
 	return versions.find(api_version) != versions.end();
 }
 
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -376,7 +376,7 @@ enum SaveLoadVersion : uint16_t {
 	SLV_MAX_LOAN_FOR_COMPANY,               ///< 330  PR#11224 Separate max loan for each company.
 	SLV_DEPOT_UNBUNCHING,                   ///< 331  PR#11945 Allow unbunching shared order vehicles at a depot.
 	SLV_AI_LOCAL_CONFIG,                    ///< 332  PR#12003 Config of running AI is stored inside Company.
-	SLV_SCRIPT_RANDOMIZER,                  ///< 333  PR#12063 Save script randomizers.
+	SLV_SCRIPT_RANDOMIZER,                  ///< 333  PR#12063 v14.0 Save script randomizers.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
 };
diff --git a/src/script/api/ai_changelog.hpp b/src/script/api/ai_changelog.hpp
--- a/src/script/api/ai_changelog.hpp
+++ b/src/script/api/ai_changelog.hpp
@@ -13,10 +13,12 @@
  * functions may still be available if you return an older API version
  * in GetAPIVersion() in info.nut.
  *
- * \b 14.0
+ * \b 15.0
  *
  * This version is not yet released. The following changes are not set in stone yet.
  *
+ * \b 14.0
+ *
  * API additions:
  * \li AITimeMode
  * \li AITown::ROAD_LAYOUT_RANDOM
diff --git a/src/script/api/game_changelog.hpp b/src/script/api/game_changelog.hpp
--- a/src/script/api/game_changelog.hpp
+++ b/src/script/api/game_changelog.hpp
@@ -13,10 +13,12 @@
  * functions may still be available if you return an older API version
  * in GetAPIVersion() in info.nut.
  *
- * \b 14.0
+ * \b 15.0
  *
  * This version is not yet released. The following changes are not set in stone yet.
  *
+ * \b 14.0
+ *
  * API additions:
  * \li GSIndustry::GetConstructionDate
  * \li GSAsyncMode