diff --git a/cmake/QtAutoDetect.cmake b/cmake/QtAutoDetect.cmake
index a994fc5e55f..cab40b5e646 100644
--- a/cmake/QtAutoDetect.cmake
+++ b/cmake/QtAutoDetect.cmake
@@ -478,6 +478,12 @@ function(qt_auto_detect_integrity)
     endif()
 endfunction()
 
+# Save the build type before project() might set one.
+# This allows us to determine if the user has set an explicit build type that we should use.
+function(qt_auto_detect_cmake_build_type)
+    set(__qt_auto_detect_cmake_build_type_before_project_call "${CMAKE_BUILD_TYPE}" PARENT_SCOPE)
+endfunction()
+
 # Let CMake load our custom platform modules.
 # CMake-provided platform modules take precedence.
 if(NOT QT_AVOID_CUSTOM_PLATFORM_MODULES)
@@ -497,3 +503,4 @@ qt_auto_detect_wasm()
 qt_auto_detect_win32_arm()
 qt_auto_detect_linux_x86()
 qt_auto_detect_integrity()
+qt_auto_detect_cmake_build_type()
diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
index caf342214e7..d8c4be7466c 100644
--- a/cmake/QtSetup.cmake
+++ b/cmake/QtSetup.cmake
@@ -49,7 +49,19 @@ unset(QT_EXTRA_BUILD_INTERNALS_VARS)
 # Save the global property in a variable to make it available to feature conditions.
 get_property(QT_GENERATOR_IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG)
 
-if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+# Try to detect if an explicit CMAKE_BUILD_TYPE was set by the user.
+# CMake sets CMAKE_BUILD_TYPE_INIT to Debug on most Windows platforms and doesn't set
+# anything for UNIXes. CMake assigns CMAKE_BUILD_TYPE_INIT to CMAKE_BUILD_TYPE during
+# first project() if CMAKE_BUILD_TYPE has no previous value.
+# We use extra information about the state of CMAKE_BUILD_TYPE before the first
+# project() call that's set in QtAutodetect.
+# STREQUAL check needs to have expanded variables because an undefined var is not equal
+# to an empty defined var.
+# See also qt_internal_force_set_cmake_build_type_conditionally which is used
+# to set the build type when building other repos or tests.
+if("${CMAKE_BUILD_TYPE}" STREQUAL "${CMAKE_BUILD_TYPE_INIT}"
+    AND NOT __qt_auto_detect_cmake_build_type_before_project_call
+    AND NOT CMAKE_CONFIGURATION_TYPES)
   message(STATUS "Setting build type to '${_default_build_type}' as none was specified.")
   set(CMAKE_BUILD_TYPE "${_default_build_type}" CACHE STRING "Choose the type of build." FORCE)
   set_property(CACHE CMAKE_BUILD_TYPE
diff --git a/config_help.txt b/config_help.txt
index f35ec4cc24c..7be06c7f9f3 100644
--- a/config_help.txt
+++ b/config_help.txt
@@ -64,10 +64,13 @@ Build options:
   -cmake-file-api ...... Let CMake store build metadata for loading the build
                          into an IDE. [no; yes if -developer-build]
   -no-guess-compiler ... Do not guess the compiler from the target mkspec.
-  -release ............. Build Qt with debugging turned off [yes]
-  -debug ............... Build Qt with debugging turned on [no]
-  -debug-and-release ... Build two versions of Qt, with and without
-                         debugging turned on [yes] (Apple and Windows only)
+  -release ............. Build Qt with optimizations and without debug
+                         symbols [yes]
+                         Note that -developer-build implies -debug unless
+                         -release is also explicitly specified
+  -debug ............... Build Qt without optimizations and with debug symbols
+                         [no]
+  -debug-and-release ... Build two versions of Qt in one build tree [no]
   -optimize-debug ...... Enable debug-friendly optimizations in debug builds
                          [auto] (Not supported with MSVC or Clang toolchains)
   -optimize-size ....... Optimize release builds for size instead of speed [no]
@@ -80,7 +83,8 @@ Build options:
                          sections. [auto for static builds, otherwise no]
   -force-asserts ....... Enable Q_ASSERT even in release builds [no]
   -developer-build ..... Compile and link Qt for developing Qt itself
-                         (exports for auto-tests, extra checks, etc.) [no]
+                         (exports for auto-tests, extra checks, implies
+                         -no-prefix, etc.) [no]
 
   -shared .............. Build shared Qt libraries [yes] (no for UIKit)
   -static .............. Build static Qt libraries [no] (yes for UIKit)