diff --git a/database-seeds/scripts/rerunners/iidx/iidx-mdb-parse/merge-mdb.ts b/database-seeds/scripts/rerunners/iidx/iidx-mdb-parse/merge-mdb.ts
index e3e043adb..52030b415 100644
--- a/database-seeds/scripts/rerunners/iidx/iidx-mdb-parse/merge-mdb.ts
+++ b/database-seeds/scripts/rerunners/iidx/iidx-mdb-parse/merge-mdb.ts
@@ -83,6 +83,15 @@ function isInBlacklist(str: string) {
 }
 
 async function ParseIIDXMDB() {
+	// omni XOR -omni in version name
+	// either both are true, or both are false
+	// if they don't match, that's probably a mistake
+	if (options.omni !== options.version.endsWith("-omni")) {
+		throw new Error(
+			`Using --omni flag, but the version you provided was ${options.version}, which doesn't look like an omnimix version.`
+		);
+	}
+
 	const mdbCharts = await ParseIIDXData(
 		options.basedir,
 		options.index,