diff --git a/planner.c b/planner.c
index d6efb61f1..a4aacc053 100644
--- a/planner.c
+++ b/planner.c
@@ -879,6 +879,11 @@ bool trial_ascent(int trial_depth, int stoplevel, int avg_depth, int bottom_time
 	bool clear_to_ascend = true;
 	char *trial_cache = NULL;
 
+	// Don't do a trail ascent but check if the ceiling is above the next stoplevel.
+	// This does not sound like a relevant question but it seems the original VPM-B implementation does that.
+	if (prefs.check_ceiling_before_ascent)
+		return (deco_allowed_depth(tissue_tolerance, surface_pressure, &displayed_dive, 1) <= stoplevel);
+
 	cache_deco_state(tissue_tolerance, &trial_cache);
 	while (trial_depth > stoplevel) {
 		int deltad = ascent_velocity(trial_depth, avg_depth, bottom_time) * TIMESTEP;
diff --git a/pref.h b/pref.h
index e471add73..953003a2d 100644
--- a/pref.h
+++ b/pref.h
@@ -97,6 +97,7 @@ struct preferences {
 	bool display_transitions;
 	bool safetystop;
 	bool switch_at_req_stop;
+	bool check_ceiling_before_ascent;
 	int reserve_gas;
 	int min_switch_duration; // seconds
 	int bottomsac;
diff --git a/subsurfacestartup.c b/subsurfacestartup.c
index 18d00d374..ba0969a10 100644
--- a/subsurfacestartup.c
+++ b/subsurfacestartup.c
@@ -48,6 +48,7 @@ struct preferences default_prefs = {
 	.doo2breaks = false,
 	.drop_stone_mode = false,
 	.switch_at_req_stop = false,
+	.check_ceiling_before_ascent = false,
 	.min_switch_duration = 60,
 	.last_stop = false,
 	.verbatim_plan = false,