diff --git a/dive.h b/dive.h
index d4bce9d6e..09a4dda17 100644
--- a/dive.h
+++ b/dive.h
@@ -124,14 +124,6 @@ static inline bool gasmix_is_air(const struct gasmix *gasmix)
 	return (he == 0) && (o2 == 0 || ((o2 >= O2_IN_AIR - 1) && (o2 <= O2_IN_AIR + 1)));
 }
 
-/* in the planner we use a null gasmix to indicate that we keep using the gas as before
- * this is BAD as a null gasmix can also be interpreted as air.
- * DANGER DANGER DANGER */
-static inline bool gasmix_is_null(const struct gasmix *gasmix)
-{
-	return gasmix->he.permille == 0 && gasmix->o2.permille == 0;
-}
-
 /* Linear interpolation between 'a' and 'b', when we are 'part'way into the 'whole' distance from a to b */
 static inline int interpolate(int a, int b, int part, int whole)
 {
diff --git a/planner.c b/planner.c
index 31ba3310c..768344caa 100644
--- a/planner.c
+++ b/planner.c
@@ -292,8 +292,6 @@ static void create_dive_from_plan(struct diveplan *diveplan, bool track_gas)
 			dp = dp->next;
 			continue;
 		}
-		if (gasmix_is_null(&gasmix))
-			gasmix = oldgasmix;
 
 		/* Check for SetPoint change */
 		if (oldpo2 != po2) {
@@ -566,11 +564,8 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool
 		nextdp = dp->next;
 		while (nextdp && nextdp->time == 0)
 			nextdp = nextdp->next;
-		if (nextdp) {
+		if (nextdp)
 			newgasmix = nextdp->gasmix;
-			if (gasmix_is_null(&newgasmix))
-				newgasmix = gasmix;
-		}
 		/* do we want to skip this leg as it is devoid of anything useful? */
 		if (!dp->entered &&
 		    gasmix_distance(&gasmix, &newgasmix) == 0 &&