diff --git a/build/windows/installer/3_dist-gimp-inno.ps1 b/build/windows/installer/3_dist-gimp-inno.ps1
index b932f9baae..eee28f8ad4 100644
--- a/build/windows/installer/3_dist-gimp-inno.ps1
+++ b/build/windows/installer/3_dist-gimp-inno.ps1
@@ -97,6 +97,13 @@ ForEach ($line in $(Select-String 'define' $CONFIG_PATH -AllMatches))
   {
     Invoke-Expression $($line -replace '^.*#' -replace 'define ','$' -replace ' ','=')
   }
+#Meson don't support C++ style comments. See: https://github.com/mesonbuild/meson/issues/14260
+$CLEANCONFIG_PATH ="$(Split-Path -Parent $CONFIG_PATH)\config_clean.h"
+if (Test-Path $CLEANCONFIG_PATH)
+  {
+    Remove-Item $CLEANCONFIG_PATH -Force
+  }
+(Get-Content $CONFIG_PATH -Raw) -replace '/\*[\s\S]*?\*/', '' | Set-Content $CLEANCONFIG_PATH
 
 ## Get CUSTOM_GIMP_VERSION (GIMP version as we display for users in installer)
 $CUSTOM_GIMP_VERSION = $GIMP_VERSION
diff --git a/build/windows/installer/base_gimp3264.iss b/build/windows/installer/base_gimp3264.iss
index cf4a124f96..5f5584cc11 100644
--- a/build/windows/installer/base_gimp3264.iss
+++ b/build/windows/installer/base_gimp3264.iss
@@ -82,27 +82,27 @@
 
 ;2 GLOBAL VARIABLES SET BY PARAMS
 ;Meson don't support C++ style comments. See: https://github.com/mesonbuild/meson/issues/14260
-#include BUILD_DIR + "\build\windows\installer\config_clean.h"
+#include BUILD_DIR + "\config_clean.h"
 
 ;Main GIMP versions:
 ;Get GIMP_MUTEX_VERSION (used for internal versioning control)
-#if Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != ""
+#if Defined(GIMP_UNSTABLE)
 	#define GIMP_MUTEX_VERSION GIMP_APP_VERSION
 #else
 	#define GIMP_MUTEX_VERSION=Copy(GIMP_APP_VERSION,1,Pos(".",GIMP_APP_VERSION)-1)
 #endif
 ;Get FULL_GIMP_VERSION (used by ITs)
 #define ORIGINAL_GIMP_VERSION GIMP_VERSION
-#if Defined(GIMP_RC_VERSION) && GIMP_RC_VERSION != ""
+#if Defined(GIMP_RC_VERSION)
 	#define GIMP_VERSION=Copy(GIMP_VERSION,1,Pos("-",GIMP_VERSION)-1)
 #endif
-#if !Defined(REVISION) || REVISION=="0" || REVISION==""
+#if !Defined(REVISION) || REVISION=="0"
 	#define FULL_GIMP_VERSION GIMP_VERSION + "." + "0"
 #else
 	#define FULL_GIMP_VERSION GIMP_VERSION + "." + REVISION
 #endif
 ;Get CUSTOM_GIMP_VERSION (that the users see)
-#if !Defined(REVISION) || REVISION=="0" || REVISION==""
+#if !Defined(REVISION) || REVISION=="0"
 	#define CUSTOM_GIMP_VERSION ORIGINAL_GIMP_VERSION
 #else
 	#define CUSTOM_GIMP_VERSION ORIGINAL_GIMP_VERSION + "-" + REVISION
@@ -157,7 +157,7 @@ AppPublisher=The GIMP Team
 AppPublisherURL=https://www.gimp.org/
 ;ControlPanel 'HelpLink'
 AppSupportURL=https://www.gimp.org/docs/
-#if Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != ""
+#if Defined(GIMP_UNSTABLE)
 	;ControlPanel 'URLUpdateInfo'
 	AppUpdatesURL=https://www.gimp.org/downloads/devel/
 #else
@@ -417,7 +417,7 @@ Type: files; Name: "{autodesktop}\{reg:HKA\SOFTWARE\Microsoft\Windows\CurrentVer
 Type: filesandordirs; Name: "{app}\lib\babl-0.1"
 Type: filesandordirs; Name: "{app}\lib\gegl-0.4"
 ;This was bunbled in 3.0 RC1 but not needed since the "Debug" menu is hidden in stable releases
-#if (!Defined(GIMP_UNSTABLE) || GIMP_UNSTABLE=="") && (Defined(GIMP_RELEASE) && GIMP_RELEASE != "")
+#if !Defined(GIMP_UNSTABLE) && Defined(GIMP_RELEASE)
 	Type: files; Name: "{app}\bin\dot.exe"
 #endif
 ;No need to all these python binaries shipped in 3.0 RC1
@@ -678,7 +678,7 @@ begin
 end;
 
 function InitializeSetup(): Boolean;
-#if (Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != "") || (Defined(GIMP_RC_VERSION) && GIMP_RC_VERSION != "") || (!Defined(GIMP_RELEASE) || GIMP_RELEASE=="") || Defined(DEVEL_WARNING)
+#if Defined(GIMP_UNSTABLE) || Defined(GIMP_RC_VERSION) || !Defined(GIMP_RELEASE)|| Defined(DEVEL_WARNING)
 var Message,Buttons: TArrayOfString;
 #endif
 begin
@@ -697,7 +697,7 @@ begin
 		exit;
 
 //Unstable version warning
-#if (Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != "") || (Defined(GIMP_RC_VERSION) && GIMP_RC_VERSION != "") || (!Defined(GIMP_RELEASE) || GIMP_RELEASE=="") || Defined(DEVEL_WARNING)
+#if Defined(GIMP_UNSTABLE) || Defined(GIMP_RC_VERSION) || !Defined(GIMP_RELEASE) || Defined(DEVEL_WARNING)
 	Explode(Message, CustomMessage('DevelopmentWarning'), #13#10);
 	SetArrayLength(Buttons,2);
 	Buttons[0] := CustomMessage('DevelopmentButtonContinue');
@@ -1541,7 +1541,7 @@ end;
 
 
 //7.2 INSTALL: show GIMP text (aka billboard) above progress bar
-#if Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != ""
+#if Defined(GIMP_UNSTABLE)
 const
 	GIMP_URL = 'https://gimp.org/downloads/devel/';
 #else
@@ -1660,7 +1660,7 @@ begin
 		InterpFile := ExpandConstant('{app}\lib\gimp\{#GIMP_PKGCONFIG_VERSION}\interpreters\pygimp.interp');
     DebugMsg('PrepareInterp','Writing interpreter file for gimp-python: ' + InterpFile);
 
-#if (Defined(GIMP_UNSTABLE) && GIMP_UNSTABLE != "") || (!Defined(GIMP_RELEASE) || GIMP_RELEASE=="")
+#if Defined(GIMP_UNSTABLE) || !Defined(GIMP_RELEASE)
 		//python.exe is prefered in unstable versions because of error output
 		#define PYTHON="python.exe"
 #else
diff --git a/build/windows/installer/config_clean.h.in b/build/windows/installer/config_clean.h.in
deleted file mode 100644
index 2b8ff8332c..0000000000
--- a/build/windows/installer/config_clean.h.in
+++ /dev/null
@@ -1,15 +0,0 @@
-// This file shouldn't even exist, but Meson unfortunately do
-// not support C++ style comments. See: https://github.com/mesonbuild/meson/issues/14260
-
-#define GIMP_APP_VERSION "@GIMP_APP_VERSION@"
-
-#define GIMP_VERSION "@GIMP_VERSION@"
-
-#define GIMP_PKGCONFIG_VERSION "@GIMP_PKGCONFIG_VERSION@"
-
-
-#define GIMP_RELEASE "@GIMP_RELEASE@"
- 
-#define GIMP_UNSTABLE "@GIMP_UNSTABLE@"
-
-#define GIMP_RC_VERSION "@GIMP_RC_VERSION@"
diff --git a/build/windows/installer/meson.build b/build/windows/installer/meson.build
deleted file mode 100644
index f04f0fc04c..0000000000
--- a/build/windows/installer/meson.build
+++ /dev/null
@@ -1,24 +0,0 @@
-## This file shouldn't even exist, but Meson unfortunately do
-## not support C++ style comments. See: https://github.com/mesonbuild/meson/issues/14260
-
-installer_conf = configuration_data()
-installer_conf.set('GIMP_APP_VERSION',  gimp_app_version)
-installer_conf.set('GIMP_VERSION',  gimp_version)
-installer_conf.set('GIMP_PKGCONFIG_VERSION',  gimp_api_version)
-
-installer_conf.set('GIMP_RELEASE', release ? 1 : '')
-if gimp_unstable != false
-  installer_conf.set('GIMP_UNSTABLE', gimp_unstable)
-endif
-if gimp_rc_version != false
-  installer_conf.set('GIMP_RC_VERSION', gimp_rc_version)
-endif
-
-configure_file(
-  input : 'config_clean.h.in',
-  output: 'config_clean.h',
-  configuration: installer_conf
-)
-
-
-subdir('lang')
diff --git a/meson.build b/meson.build
index 7780a5869f..9e2b03d0f1 100644
--- a/meson.build
+++ b/meson.build
@@ -89,25 +89,19 @@ conf.set_quoted('GIMP_VERSION', gimp_version)
 
 # GIMP_UNSTABLE tells if we are on an unstable or stable development branch.
 stable = (gimp_app_version_minor % 2 == 0)
-gimp_unstable = stable ? false : 1
-if gimp_unstable != false
-  conf.set('GIMP_UNSTABLE', gimp_unstable)
-endif
+conf.set('GIMP_UNSTABLE', stable ? false : 1)
 
 # GIMP_RELEASE tells if this is a release or in-between release (git) code.
 release = (gimp_app_version_micro % 2 == 0)
 conf.set('GIMP_RELEASE', release ? 1 : false)
 
 # GIMP_RC_VERSION can only be set on release candidates.
-gimp_rc_version = release and gimp_app_version_rc > 0 ? gimp_app_version_rc : false
-if gimp_rc_version != false
-  conf.set('GIMP_RC_VERSION', gimp_rc_version)
-endif
+conf.set('GIMP_RC_VERSION', release and gimp_app_version_rc > 0 ? gimp_app_version_rc : false)
 # GIMP_IS_GIT can only be set during development of a RC.
 conf.set('GIMP_IS_RC_GIT', gimp_rc_git ? 1 : false)
 
 # Mutex version
-if gimp_unstable != false
+if not stable
   conf.set_quoted('GIMP_MUTEX_VERSION', gimp_app_version)
 else
   conf.set_quoted('GIMP_MUTEX_VERSION', gimp_app_version_major.to_string())
@@ -2075,7 +2069,7 @@ subdir('devel-docs')
 # Inno Windows installer
 if get_option('windows-installer')
   subdir('po-windows-installer')
-  subdir('build/windows/installer')
+  subdir('build/windows/installer/lang')
 endif
 
 pkgconfig.generate(libgimp,
diff --git a/plug-ins/python/meson.build b/plug-ins/python/meson.build
index 02897d999b..04dc3dcb45 100644
--- a/plug-ins/python/meson.build
+++ b/plug-ins/python/meson.build
@@ -41,7 +41,7 @@ endforeach
 # Fallback fix to the problem of non-configured interpreters (needed by MSIX)
 if platform_windows and not meson.is_cross_build() and python.found()
   python_config = configuration_data()
-  if gimp_unstable or not release
+  if not stable or not release
     #python.exe is prefered in unstable versions because of error output
     python_config.set('PYTHON_EXE', 'python.exe')
   else