diff --git a/core/planner.cpp b/core/planner.cpp
index a0eb93151..3a6b50d40 100644
--- a/core/planner.cpp
+++ b/core/planner.cpp
@@ -799,7 +799,7 @@ bool plan(struct deco_state *ds, struct diveplan *diveplan, struct dive *dive, i
 				      po2, diveplan->surface_pressure / 1000.0, dive, divemode) &&
 			 enough_gas(dive, current_cylinder) && clock < 6 * 3600);
 
-		// We did stay one DECOTIMESTEP too many.
+		// We did stay one timestep too many.
 		// In the best of all worlds, we would roll back also the last add_segment in terms of caching deco state, but
 		// let's ignore that since for the eventual ascent in recreational mode, nobody looks at the ceiling anymore,
 		// so we don't really have to compute the deco state.
diff --git a/core/planner.h b/core/planner.h
index d48c55e8f..0d65acf37 100644
--- a/core/planner.h
+++ b/core/planner.h
@@ -8,8 +8,6 @@
 #include "units.h"
 #include "divemode.h"
 
-#define DECOTIMESTEP 60 /* seconds. Unit of deco stop times */
-
 /* this should be converted to use our types */
 struct divedatapoint {
 	int time;
diff --git a/qt-models/diveplannermodel.cpp b/qt-models/diveplannermodel.cpp
index 5c51a2de4..d7573db89 100644
--- a/qt-models/diveplannermodel.cpp
+++ b/qt-models/diveplannermodel.cpp
@@ -27,6 +27,8 @@
 
 #define UNIT_FACTOR ((prefs.units.length == units::METERS) ? 1000.0 / 60.0 : feet_to_mm(1.0) / 60.0)
 
+static constexpr int decotimestep = 60; // seconds
+
 CylindersModel *DivePlannerPointsModel::cylindersModel()
 {
 	return &cylinders;
@@ -1078,7 +1080,7 @@ void DivePlannerPointsModel::updateDiveProfile()
 	struct deco_state plan_deco_state;
 
 	memset(&plan_deco_state, 0, sizeof(struct deco_state));
-	plan(&plan_deco_state, &diveplan, d, DECOTIMESTEP, stoptable, cache, isPlanner(), false);
+	plan(&plan_deco_state, &diveplan, d, decotimestep, stoptable, cache, isPlanner(), false);
 	updateMaxDepth();
 
 	if (isPlanner() && shouldComputeVariations()) {
@@ -1290,7 +1292,7 @@ void DivePlannerPointsModel::createPlan(bool replanCopy)
 	createTemporaryPlan();
 
 	struct decostop stoptable[60];
-	plan(&ds_after_previous_dives, &diveplan, d, DECOTIMESTEP, stoptable, cache, isPlanner(), true);
+	plan(&ds_after_previous_dives, &diveplan, d, decotimestep, stoptable, cache, isPlanner(), true);
 
 	if (shouldComputeVariations()) {
 		struct diveplan *plan_copy;