diff --git a/icinga-installer/icinga-installer.cpp b/icinga-installer/icinga-installer.cpp
index f87debb63..5f680f4e3 100644
--- a/icinga-installer/icinga-installer.cpp
+++ b/icinga-installer/icinga-installer.cpp
@@ -142,7 +142,7 @@ static int UpgradeNSIS(void)
 	if (!Utility::PathExists(uninstallerPath))
 		return 0;
 
-	ExecuteCommand(uninstallerPath, "/S \"_?=" + installPath + "\"");
+	ExecuteCommand(uninstallerPath, "/S _?=" + installPath);
 
 	_unlink(uninstallerPath.CStr());