diff --git a/core/threaded/reactor_threaded.c b/core/threaded/reactor_threaded.c
index 61ab5a44a..6a685b4fa 100644
--- a/core/threaded/reactor_threaded.c
+++ b/core/threaded/reactor_threaded.c
@@ -196,7 +196,7 @@ void lf_set_present(lf_port_base_t* port) {
 }
 
 bool wait_until(instant_t wait_until_time, lf_cond_t* condition) {
-  if (!fast) {
+  if (!fast || (wait_until_time == FOREVER && keepalive_specified)) {
     LF_PRINT_DEBUG("-------- Waiting until physical time " PRINTF_TIME, wait_until_time - start_time);
     // Check whether we actually need to wait, or if we have already passed the timepoint.
     interval_t wait_duration = wait_until_time - lf_time_physical();