diff --git a/backend/src/main/java/com/github/eostermueller/snail4j/systemproperty/OneTimeConfigChanger.java b/backend/src/main/java/com/github/eostermueller/snail4j/systemproperty/OneTimeConfigChanger.java
new file mode 100644
index 0000000..7b18a2b
--- /dev/null
+++ b/backend/src/main/java/com/github/eostermueller/snail4j/systemproperty/OneTimeConfigChanger.java
@@ -0,0 +1,8 @@
+package com.github.eostermueller.snail4j.systemproperty;
+
+import com.github.eostermueller.snail4j.Snail4jException;
+import com.github.eostermueller.snail4j.launcher.Configuration;
+
+public interface OneTimeConfigChanger {
+	void oneTimeChange(Configuration cfg) throws Snail4jException;
+}