diff --git a/contrib/msi/build-msi-gui.sh b/contrib/msi/build-msi-gui.sh
index 85e3c191..e528b285 100644
--- a/contrib/msi/build-msi-gui.sh
+++ b/contrib/msi/build-msi-gui.sh
@@ -309,7 +309,7 @@ cat > wix.xml << EOF
     <CustomAction Id="LaunchApplication"
       FileKey="MeshUI"
       Impersonate="yes" 
-      ExeCommand="[MeshInstallFolder]ui\index.html" 
+      ExeCommand='"[MeshInstallFolder]ui\index.html"'
       Return="asyncNoWait" />
 
     <!-- Step 3: Include the custom action -->