--- a/src/VBox/HostDrivers/Support/SUPR3HardenedMain.cpp
+++ b/src/VBox/HostDrivers/Support/SUPR3HardenedMain.cpp
@@ -2131,6 +2131,11 @@ static void supR3HardenedMainPurgeEnvironment(char **envp)
         /** @todo Call NT API to do the same. */
 #endif
     }
+
+    /*
+     * NixOS hack: Set QT_PLUGIN_PATH to make Qt find plugins.
+     */
+    setenv("QT_PLUGIN_PATH", "@qtPluginPath@", /*overwrite=*/ 1);
 }