diff --git a/ChangeLog.txt b/ChangeLog.txt
index b3406f9b..4cbce699 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -14,6 +14,9 @@ Broker:
   mosquitto 1.5 or earlier is loaded. Closes #3439.
 - Limit auto_id_prefix to 50 characters. Closes #3440.
 
+Windows:
+- Installer will not overwrite an existing mosquitto.conf
+
 
 2.0.22 - 2025-07-11
 ===================
diff --git a/installer/mosquitto.nsi b/installer/mosquitto.nsi
index 5a936c70..b6ff260b 100644
--- a/installer/mosquitto.nsi
+++ b/installer/mosquitto.nsi
@@ -57,7 +57,6 @@ Section "Files" SecInstall
 	File "..\build\plugins\dynamic-security\Release\mosquitto_dynamic_security.dll"
 	File "..\aclfile.example"
 	File "..\ChangeLog.txt"
-	File "..\mosquitto.conf"
 	File "..\NOTICE.md"
 	File "..\pwfile.example"
 	File "..\README.md"
@@ -67,6 +66,10 @@ Section "Files" SecInstall
 	File "..\edl-v10"
 	File "..\epl-v20"
 
+	SetOverwrite off
+	File "..\mosquitto.conf"
+	SetOverwrite on
+
 	File "..\build\vcpkg_installed\x86-windows\bin\cjson.dll"
 	File "..\build\vcpkg_installed\x86-windows\bin\libcrypto-3.dll"
 	File "..\build\vcpkg_installed\x86-windows\bin\libssl-3.dll"
diff --git a/installer/mosquitto64.nsi b/installer/mosquitto64.nsi
index efc88636..d1459a9a 100644
--- a/installer/mosquitto64.nsi
+++ b/installer/mosquitto64.nsi
@@ -58,7 +58,6 @@ Section "Files" SecInstall
 	File "..\build64\plugins\dynamic-security\Release\mosquitto_dynamic_security.dll"
 	File "..\aclfile.example"
 	File "..\ChangeLog.txt"
-	File "..\mosquitto.conf"
 	File "..\NOTICE.md"
 	File "..\pwfile.example"
 	File "..\README.md"
@@ -68,6 +67,10 @@ Section "Files" SecInstall
 	File "..\edl-v10"
 	File "..\epl-v20"
 
+	SetOverwrite off
+	File "..\mosquitto.conf"
+	SetOverwrite on
+
 	File "..\build64\vcpkg_installed\x64-windows-release\bin\cjson.dll"
 	File "..\build64\vcpkg_installed\x64-windows-release\bin\libcrypto-3-x64.dll"
 	File "..\build64\vcpkg_installed\x64-windows-release\bin\libssl-3-x64.dll"