diff --git a/src/zeitansage/main.c b/src/zeitansage/main.c
index 779573b..da75f05 100644
--- a/src/zeitansage/main.c
+++ b/src/zeitansage/main.c
@@ -73,6 +73,8 @@ int main(int argc, char *argv[])
 {
 	int rc, argi;
 
+	allow_sdr = 0;
+
 	/* init system specific tones */
 	init_samples();