diff --git a/afsk/telem.c b/afsk/telem.c
index 9b3ec244..fa6277f8 100644
--- a/afsk/telem.c
+++ b/afsk/telem.c
@@ -126,17 +126,17 @@ struct SensorData read_sensor_data(struct SensorConfig sensor) {
 struct SensorConfig config_sensor(char *bus, int address,  int milliAmps) {
     struct SensorConfig data;
     FILE *i2cdetect = popen("timeout 5 i2cdetect -y 0", "r");
-    printf("i2cdetect 0 output: %s\n", getc(i2cdetect));
+    printf("i2cdetect 0 output: %d\n", getc(i2cdetect));
     int error = pclose(i2cdetect)/256;
     printf("i2cdetect 0 error: %d \n", error);
 
     i2cdetect = popen("timeout 5 i2cdetect -y 1", "r");
-    printf("i2cdetect 1 output: %s\n", getc(i2cdetect));
+    printf("i2cdetect 1 output: %d\n", getc(i2cdetect));
     error = pclose(i2cdetect)/256;
     printf("i2cdetect 1 error: %d \n", error);
 
     i2cdetect = popen("timeout 5 i2cdetect -y 3", "r");
-    printf("i2cdetect 3 output: %s\n", getc(i2cdetect));
+    printf("i2cdetect 3 output: %d\n", getc(i2cdetect));
     error = pclose(i2cdetect)/256;
     printf("i2cdetect 3 error: %d \n", error);