diff --git a/include/rtl-sdr.h b/include/rtl-sdr.h
index ec0b4c8..5eef94a 100644
--- a/include/rtl-sdr.h
+++ b/include/rtl-sdr.h
@@ -138,7 +138,7 @@ enum rtlsdr_tuner {
  * Get the tuner type.
  *
  * \param dev the device handle given by rtlsdr_open()
- * \return <= 0 on error, tuner type otherwise
+ * \return RTLSDR_TUNER_UNKNOWN on error, tuner type otherwise
  */
 RTLSDR_API enum rtlsdr_tuner rtlsdr_get_tuner_type(rtlsdr_dev_t *dev);
 
diff --git a/src/librtlsdr.c b/src/librtlsdr.c
index 4e54d8e..6a92fa5 100644
--- a/src/librtlsdr.c
+++ b/src/librtlsdr.c
@@ -695,7 +695,7 @@ int rtlsdr_get_freq_correction(rtlsdr_dev_t *dev)
 enum rtlsdr_tuner rtlsdr_get_tuner_type(rtlsdr_dev_t *dev)
 {
 	if (!dev)
-		return -1;
+		return RTLSDR_TUNER_UNKNOWN;
 
 	return dev->tuner_type;
 }