diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 46021a3..10bc2b3 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -211,9 +211,7 @@ jobs:
         uses: Minionguyjpro/Inno-Setup-Action@v1.2.2
         with:
           path: windows/windows_setup.iss
-          options: /O+
-        env:
-          FLADDER_VERSION: ${{ needs.fetch-info.outputs.version_name }}
+          options: /O+ /DFLADDER_VERSION="${{ needs.fetch-info.outputs.version_name }}"
 
       - name: Archive Windows portable artifact
         uses: actions/upload-artifact@v4.0.0
diff --git a/windows/windows_setup.iss b/windows/windows_setup.iss
index 17e0308..4f24eab 100644
--- a/windows/windows_setup.iss
+++ b/windows/windows_setup.iss
@@ -1,9 +1,13 @@
 #define SourcePath ".."
 
+#ifndef FLADDER_VERSION
+  #define FLADDER_VERSION "latest"
+#endif
+
 [Setup]
 AppId={{D573EDD5-117A-47AD-88AC-62C8EBD11DC7}
 AppName="Fladder"
-AppVersion={%FLADDER_VERSION|latest}
+AppVersion={#FLADDER_VERSION}
 AppPublisher="DonutWare"
 AppPublisherURL="https://github.com/DonutWare/Fladder"
 AppSupportURL="https://github.com/DonutWare/Fladder"