diff --git a/radio/rfsimulator/simulator.c b/radio/rfsimulator/simulator.c
index 4db78e9659..1175d9ec42 100644
--- a/radio/rfsimulator/simulator.c
+++ b/radio/rfsimulator/simulator.c
@@ -312,6 +312,9 @@ static void rfsimulator_readconfig(rfsimulator_state_t *rfsimulator) {
   /* for compatibility keep environment variable usage */
   if ( getenv("RFSIMULATOR") != NULL ) {
     rfsimulator->ip=getenv("RFSIMULATOR");
+    LOG_W(HW, "The RFSIMULATOR environment variable is deprecated and support will be removed in the future. Instead, add parameter --rfsimulator.serveraddr %s to set the server address. Note: the default is \"server\"; for the gNB/eNB, you don't have to set any configuration.\n", rfsimulator->ip);
+    LOG_I(HW, "Remove RFSIMULATOR environment variable to get rid of this message and the sleep.\n");
+    sleep(10);
   }
 
   if ( strncasecmp(rfsimulator->ip,"enb",3) == 0 ||