diff --git a/CMakeLists.txt b/CMakeLists.txt
index d88455b65f..3f77e261fa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,9 +13,10 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_BINARY_DIR)
     message(FATAL_ERROR "In-source builds not allowed. Please run \"cmake ..\" from the build directory. You may need to delete \"${CMAKE_SOURCE_DIR}/CMakeCache.txt\" first.")
 endif()
 
-# Debug mode by default.
-if(NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE Debug)
+# Default to Release build if not specified
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+  message(STATUS "No build type specified. Defaulting to RelWithDebInfo.")
+  set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING "Choose the type of build." FORCE)
 endif()
 
 if (EMSCRIPTEN)
diff --git a/COMPILING.md b/COMPILING.md
index 74e816253e..03c6b58462 100644
--- a/COMPILING.md
+++ b/COMPILING.md
@@ -94,8 +94,9 @@ cmake ..
 make
 ```
 
-For more information on how to use CMake (including how to make Release builds),
-we urge you to read [their excellent manual](https://cmake.org/cmake/help/latest/guide/user-interaction/index.html).
+Unlike vanilla OpenTTD this will make a Release build of CityMania patchpack by default. If you want debug one use `cmake -DCMAKE_BUILD_TYPE=Debug -DOPTION_USE_ASSERTS=ON ..`
+
+For more information on how to use CMake, we urge you to read [their excellent manual](https://cmake.org/cmake/help/latest/guide/user-interaction/index.html).
 
 ## CMake Options
 
@@ -107,9 +108,8 @@ builds.
    in case of a crash.
 - `-DOPTION_DEDICATED=ON`: build OpenTTD without a GUI. Useful if you are
    running a headless server, as it requires less libraries to operate.
-- `-DOPTION_USE_ASSERTS=OFF`: disable asserts. Use with care, as assert
-   statements capture early signs of trouble. Release builds have them
-   disabled by default.
+- `-DOPTION_USE_ASSERTS=ON`: enable asserts. Useful for debugging, as assert
+   statements capture early signs of trouble. 
 - `-DOPTION_TOOLS_ONLY=ON`: only build tools like `strgen`. Does not build
    the game itself. Useful for cross-compiling.
 
diff --git a/cmake-ninja-clang-release.sh b/cmake-ninja-clang-release.sh
new file mode 100644
index 0000000000..84f7de7003
--- /dev/null
+++ b/cmake-ninja-clang-release.sh
@@ -0,0 +1,2 @@
+# Use ninja and clang for faster build time, use Release and no asserts for best performance
+cmake .. -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -DOPTION_USE_ASSERTS=OFF -DCMAKE_COLOR_DIAGNOSTICS=ON ..
diff --git a/cmake/Options.cmake b/cmake/Options.cmake
index 38d708c717..63e0d7337b 100644
--- a/cmake/Options.cmake
+++ b/cmake/Options.cmake
@@ -56,7 +56,7 @@ function(set_options)
 
     option(OPTION_DEDICATED "Build dedicated server only (no GUI)" OFF)
     option(OPTION_INSTALL_FHS "Install with Filesystem Hierarchy Standard folders" ${DEFAULT_OPTION_INSTALL_FHS})
-    option(OPTION_USE_ASSERTS "Use assertions; leave enabled for nightlies, betas, and RCs" ON)
+    option(OPTION_USE_ASSERTS "Use assertions; Enable for nightlies, betas, and RCs" OFF)
     option(OPTION_USE_NSIS "Use NSIS to create windows installer; enable only for stable releases" OFF)
     option(OPTION_TOOLS_ONLY "Build only tools target" OFF)
     option(OPTION_DOCS_ONLY "Build only docs target" OFF)