diff --git a/src/drivers/gnss/septentrio/sbf/decoder.cpp b/src/drivers/gnss/septentrio/sbf/decoder.cpp
index 7f9720bd82..308d26ef9b 100644
--- a/src/drivers/gnss/septentrio/sbf/decoder.cpp
+++ b/src/drivers/gnss/septentrio/sbf/decoder.cpp
@@ -102,7 +102,7 @@ Decoder::State Decoder::add_byte(uint8_t byte)
 
 BlockID Decoder::id() const
 {
-	return _state == State::Done ? _message.header.id_number : BlockID::Invalid;
+	return _state == State::Done ? static_cast<BlockID>(_message.header.id_number) : BlockID::Invalid;
 }
 
 int Decoder::parse(Header *header) const
diff --git a/src/drivers/gnss/septentrio/sbf/messages.h b/src/drivers/gnss/septentrio/sbf/messages.h
index 487a40054c..8b7ca0c95e 100644
--- a/src/drivers/gnss/septentrio/sbf/messages.h
+++ b/src/drivers/gnss/septentrio/sbf/messages.h
@@ -98,7 +98,7 @@ struct Header {
 	uint8_t sync1;
 	uint8_t sync2;
 	uint16_t crc;
-	BlockID id_number: 13;
+	uint16_t id_number: 13;
 	uint16_t id_revision: 3;
 	uint16_t length;
 	uint32_t tow;
@@ -143,7 +143,7 @@ struct PVTGeodetic {
 		MissingBaseStationCoordinates = 9,
 		MissingRequiredRTKFixedPosition = 10,
 	};
-	ModeType mode_type: 4;
+	uint8_t mode_type: 4;
 	uint8_t mode_reserved: 2;
 	uint8_t mode_base_fixed: 1;
 	uint8_t mode_2d: 1;
@@ -314,8 +314,8 @@ struct AttEuler {
 		InsufficientMeasurements = 1,
 	};
 	uint8_t nr_sv;
-	Error error_aux1: 2;
-	Error error_aux2: 2;
+	uint8_t error_aux1: 2;
+	uint8_t error_aux2: 2;
 	uint8_t error_reserved: 3;
 	uint8_t error_not_requested: 1;
 	uint16_t mode;
@@ -334,8 +334,8 @@ struct AttCovEuler {
 		InsufficientMeasurements = 1,
 	};
 	uint8_t reserved;
-	Error error_aux1: 2;
-	Error error_aux2: 2;
+	uint8_t error_aux1: 2;
+	uint8_t error_aux2: 2;
 	uint8_t error_reserved: 3;
 	uint8_t error_not_requested: 1;
 	float cov_headhead;
diff --git a/src/drivers/gnss/septentrio/septentrio.cpp b/src/drivers/gnss/septentrio/septentrio.cpp
index 5fca971fb5..a5ca8a95d1 100644
--- a/src/drivers/gnss/septentrio/septentrio.cpp
+++ b/src/drivers/gnss/septentrio/septentrio.cpp
@@ -1075,7 +1075,7 @@ int SeptentrioDriver::process_message()
 			PVTGeodetic pvt_geodetic;
 
 			if (_sbf_decoder.parse(&header) == PX4_OK && _sbf_decoder.parse(&pvt_geodetic) == PX4_OK) {
-				switch (pvt_geodetic.mode_type) {
+				switch (static_cast<sbf::PVTGeodetic::ModeType>(pvt_geodetic.mode_type)) {
 				case ModeType::NoPVT:
 					_message_gps_state.fix_type = sensor_gps_s::FIX_TYPE_NONE;
 					break;
@@ -1242,8 +1242,8 @@ int SeptentrioDriver::process_message()
 
 			if (_sbf_decoder.parse(&att_euler) == PX4_OK &&
 			    !att_euler.error_not_requested &&
-			    att_euler.error_aux1 == Error::None &&
-			    att_euler.error_aux2 == Error::None &&
+			    static_cast<AttEuler::Error>(att_euler.error_aux1) == Error::None &&
+			    static_cast<AttEuler::Error>(att_euler.error_aux2) == Error::None &&
 			    att_euler.heading > k_dnu_f4_value) {
 				float heading = att_euler.heading * M_PI_F / 180.0f; // Range of degrees to range of radians in [0, 2PI].
 
@@ -1267,8 +1267,8 @@ int SeptentrioDriver::process_message()
 
 			if (_sbf_decoder.parse(&att_cov_euler) == PX4_OK &&
 			    !att_cov_euler.error_not_requested &&
-			    att_cov_euler.error_aux1 == Error::None &&
-			    att_cov_euler.error_aux2 == Error::None &&
+			    static_cast<AttCovEuler::Error>(att_cov_euler.error_aux1) == Error::None &&
+			    static_cast<AttCovEuler::Error>(att_cov_euler.error_aux2) == Error::None &&
 			    att_cov_euler.cov_headhead > k_dnu_f4_value) {
 				_message_gps_state.heading_accuracy = att_cov_euler.cov_headhead * M_PI_F / 180.0f; // Convert range of degrees to range of radians in [0, 2PI]
 			}
diff --git a/src/drivers/gnss/septentrio/septentrio_fuzz_tests.cpp b/src/drivers/gnss/septentrio/septentrio_fuzz_tests.cpp
index 94f3c6b592..a28e618ee9 100644
--- a/src/drivers/gnss/septentrio/septentrio_fuzz_tests.cpp
+++ b/src/drivers/gnss/septentrio/septentrio_fuzz_tests.cpp
@@ -45,7 +45,7 @@ TEST(SeptentrioTestDecoding, decodeMessage)
 	septentrio::sbf::message_t m{};
 	m.header.sync1 = '$';
 	m.header.sync2 = '@';
-	m.header.id_number = septentrio::sbf::BlockID::PVTGeodetic;
+	m.header.id_number = static_cast<uint16_t>(septentrio::sbf::BlockID::PVTGeodetic);
 	m.header.length = sizeof(m.header) + sizeof(septentrio::sbf::PVTGeodetic);
 	septentrio::sbf::PVTGeodetic pvt{};
 	pvt.latitude = 123;