diff --git a/src/shearwater_predator_parser.c b/src/shearwater_predator_parser.c
index 039926f..c71c9d7 100644
--- a/src/shearwater_predator_parser.c
+++ b/src/shearwater_predator_parser.c
@@ -422,11 +422,11 @@ shearwater_predator_parser_samples_foreach (dc_parser_t *abstract, dc_sample_cal
 		// Status flags.
 		unsigned int status = data[offset + 11];
 
-		// PPO2
-		sample.ppo2 = data[offset + 6] / 100.0;
-		if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
-
 		if ((status & OC) == 0) {
+			// PPO2
+			sample.ppo2 = data[offset + 6] / 100.0;
+			if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
+
 			// Setpoint
 			if (parser->petrel) {
 				sample.setpoint = data[offset + 18] / 100.0;