diff --git a/core/load-git.c b/core/load-git.c
index a5dbf9ccc..0b6d877a6 100644
--- a/core/load-git.c
+++ b/core/load-git.c
@@ -644,7 +644,7 @@ static char *parse_sample_unit(struct sample *sample, double val, char *unit)
 /*
  * If the given cylinder doesn't exist, return NO_SENSOR.
  */
-static uint8_t sanitize_sensor_id(const struct dive *d, int nr)
+static int sanitize_sensor_id(const struct dive *d, int nr)
 {
 	return d && nr >= 0 && nr < d->cylinders.nr ? nr : NO_SENSOR;
 }
diff --git a/core/parse.c b/core/parse.c
index e8161b395..fddcdeff4 100644
--- a/core/parse.c
+++ b/core/parse.c
@@ -393,7 +393,7 @@ void ws_end(struct parser_state *state)
 /*
  * If the given cylinder doesn't exist, return NO_SENSOR.
  */
-static uint8_t sanitize_sensor_id(const struct dive *d, int nr)
+static int sanitize_sensor_id(const struct dive *d, int nr)
 {
 	return d && nr >= 0 && nr < d->cylinders.nr ? nr : NO_SENSOR;
 }