diff --git a/src/field-cache.c b/src/field-cache.c
index 7f6ccd8b..7c16ae49 100644
--- a/src/field-cache.c
+++ b/src/field-cache.c
@@ -85,8 +85,9 @@ dc_field_get(dc_field_cache_t *cache, dc_field_type_t type, unsigned int flags,
 	case DC_FIELD_AVGDEPTH:
 		return DC_FIELD_VALUE(*cache, value, AVGDEPTH);
 	case DC_FIELD_GASMIX_COUNT:
-	case DC_FIELD_TANK_COUNT:
 		return DC_FIELD_VALUE(*cache, value, GASMIX_COUNT);
+	case DC_FIELD_TANK_COUNT:
+		return DC_FIELD_VALUE(*cache, value, TANK_COUNT);
 	case DC_FIELD_GASMIX:
 		if (flags >= MAXGASES)
 			break;
diff --git a/src/field-cache.h b/src/field-cache.h
index dd847e6a..c2b22ea1 100644
--- a/src/field-cache.h
+++ b/src/field-cache.h
@@ -14,6 +14,7 @@ typedef struct dc_field_cache {
 	double ATMOSPHERIC;
 	dc_divemode_t DIVEMODE;
 	unsigned int GASMIX_COUNT;
+	unsigned int TANK_COUNT;
 	dc_salinity_t SALINITY;
 	dc_gasmix_t GASMIX[MAXGASES];
 
diff --git a/src/garmin_parser.c b/src/garmin_parser.c
index 543346b5..5dd46166 100644
--- a/src/garmin_parser.c
+++ b/src/garmin_parser.c
@@ -1696,8 +1696,8 @@ garmin_parser_set_data (garmin_parser_t *garmin, const unsigned char *data, unsi
 	//
 	// There's no way to match them up unless they are an identity
 	// mapping, so having two different ones doesn't actually work.
-	if (garmin->dive.nr_sensor > garmin->cache.GASMIX_COUNT)
-		DC_ASSIGN_FIELD(garmin->cache, GASMIX_COUNT, garmin->dive.nr_sensor);
+	if (garmin->dive.nr_sensor > garmin->cache.TANK_COUNT)
+		DC_ASSIGN_FIELD(garmin->cache, TANK_COUNT, garmin->dive.nr_sensor);
 
 	for (int i = 0; i < garmin->dive.nr_sensor; i++) {
 		static const char *name[] = { "Sensor 1", "Sensor 2", "Sensor 3", "Sensor 4", "Sensor 5" };