diff --git a/src/hfp.c b/src/hfp.c
index 3da0c2b98..afe527533 100644
--- a/src/hfp.c
+++ b/src/hfp.c
@@ -183,7 +183,7 @@ static hfp_connection_t * create_hfp_connection_context(){
     context->state = HFP_IDLE;
     context->line_size = 0;
     
-    context->negotiated_codec = HFP_Codec_CVSD;
+    context->negotiated_codec = HFP_CODEC_CVSD;
     context->remote_supported_features = 0;
     context->remote_indicators_update_enabled = 0;
     context->remote_indicators_nr = 0;
diff --git a/src/hfp.h b/src/hfp.h
index 619f4dcec..91512e47d 100644
--- a/src/hfp.h
+++ b/src/hfp.h
@@ -52,8 +52,8 @@
 extern "C" {
 #endif
 
-#define HFP_Default_HF_Supported_Features 0x0000
-#define HFP_Default_AG_Supported_Features 0x0009
+#define HFP_DEFAULT_HF_SUPPORTED_FEATURES 0x0000
+#define HFP_DEFAULT_AG_SUPPORTED_FEATURES 0x0009
 
 #define HFP_MAX_NUM_CODECS 20
 #define HFP_MAX_NUM_INDICATORS 20
@@ -86,16 +86,17 @@ extern "C" {
 11: eSCO S4 (and T2) Settings Supported
 12-31: Reserved for future definition
 */
-#define HFP_Supported_Features "+BRSF"
-#define HFP_Available_Codecs "+BAC"
-#define HFP_Indicator "+CIND"
-#define HFP_Enable_Indicator_Status_Update "+CMER"
-#define HFP_Support_Call_Hold_And_Multiparty_Services "+CHLD"
-#define HFP_Generic_Status_Indicator "+BIND"
+#define HFP_SUPPORTED_FEATURES "+BRSF"
+#define HFP_AVAILABLE_CODECS "+BAC"
+#define HFP_INDICATOR "+CIND"
+#define HFP_ENABLE_INDICATOR_STATUS_UPDATE "+CMER"
+#define HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES "+CHLD"
+#define HFP_GENERIC_STATUS_INDICATOR "+BIND"
 #define HFP_OK "OK"
 
-#define HFP_Codec_CVSD 0x01
-#define HFP_Codec_mSBC 0x02
+// Codecs 
+#define HFP_CODEC_CVSD 0x01
+#define HFP_CODEC_MSBC 0x02
 
 
 typedef enum {
diff --git a/src/hfp_ag.c b/src/hfp_ag.c
index a6055ae0f..a2704d784 100644
--- a/src/hfp_ag.c
+++ b/src/hfp_ag.c
@@ -62,7 +62,7 @@
 #include "hfp_ag.h"
 
 static const char default_hfp_ag_service_name[] = "Voice gateway";
-static uint16_t hfp_supported_features = HFP_Default_HF_Supported_Features;
+static uint16_t hfp_supported_features = HFP_DEFAULT_HF_SUPPORTED_FEATURES;
 static uint8_t hfp_codecs_nr = 0;
 static uint8_t hfp_codecs[HFP_MAX_NUM_CODECS];
 
diff --git a/src/hfp_hf.c b/src/hfp_hf.c
index 6a21d6692..fe04049fd 100644
--- a/src/hfp_hf.c
+++ b/src/hfp_hf.c
@@ -63,7 +63,7 @@
 
 
 static const char default_hfp_hf_service_name[] = "Hands-Free unit";
-static uint16_t hfp_supported_features = HFP_Default_HF_Supported_Features;
+static uint16_t hfp_supported_features = HFP_DEFAULT_HF_SUPPORTED_FEATURES;
 static uint8_t hfp_codecs_nr = 0;
 static uint8_t hfp_codecs[HFP_MAX_NUM_CODECS];
 
@@ -119,14 +119,14 @@ static int store_bit(uint32_t bitmap, int position, uint8_t value){
 
 int hfp_hs_exchange_supported_features_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s=%d\r\n", HFP_Supported_Features, hfp_supported_features);
+    sprintf(buffer, "AT%s=%d\r\n", HFP_SUPPORTED_FEATURES, hfp_supported_features);
     // printf("exchange_supported_features %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
 
 int hfp_hs_retrieve_codec_cmd(uint16_t cid){
     char buffer[30];
-    int buffer_offset = snprintf(buffer, sizeof(buffer), "AT%s=", HFP_Available_Codecs);
+    int buffer_offset = snprintf(buffer, sizeof(buffer), "AT%s=", HFP_AVAILABLE_CODECS);
     join(buffer+buffer_offset, sizeof(buffer)-buffer_offset, hfp_codecs, hfp_codecs_nr);
     // printf("retrieve_codec %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
@@ -135,21 +135,21 @@ int hfp_hs_retrieve_codec_cmd(uint16_t cid){
 
 int hfp_hs_retrieve_indicators_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s=?\r\n", HFP_Indicator);
+    sprintf(buffer, "AT%s=?\r\n", HFP_INDICATOR);
     // printf("retrieve_indicators %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
 
 int hfp_hs_retrieve_indicators_status_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s?\r\n", HFP_Indicator);
+    sprintf(buffer, "AT%s?\r\n", HFP_INDICATOR);
     // printf("retrieve_indicators_status %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
 
 int hfp_hs_toggle_indicator_status_update_cmd(uint16_t cid, uint8_t activate){
     char buffer[20];
-    sprintf(buffer, "AT%s=3,0,0,%d\r\n", HFP_Enable_Indicator_Status_Update, activate);
+    sprintf(buffer, "AT%s=3,0,0,%d\r\n", HFP_ENABLE_INDICATOR_STATUS_UPDATE, activate);
     // printf("toggle_indicator_status_update %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
@@ -157,7 +157,7 @@ int hfp_hs_toggle_indicator_status_update_cmd(uint16_t cid, uint8_t activate){
 
 int hfp_hs_retrieve_can_hold_call_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s=?\r\n", HFP_Support_Call_Hold_And_Multiparty_Services);
+    sprintf(buffer, "AT%s=?\r\n", HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES);
     // printf("retrieve_can_hold_call %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
@@ -165,7 +165,7 @@ int hfp_hs_retrieve_can_hold_call_cmd(uint16_t cid){
 
 int hfp_hs_list_supported_generic_status_indicators_cmd(uint16_t cid){
     char buffer[30];
-    int buffer_offset = snprintf(buffer, sizeof(buffer), "AT%s=", HFP_Generic_Status_Indicator); 
+    int buffer_offset = snprintf(buffer, sizeof(buffer), "AT%s=", HFP_GENERIC_STATUS_INDICATOR); 
     join(buffer+buffer_offset, sizeof(buffer)-buffer_offset, hfp_indicators, hfp_indicators_nr); 
     // printf("list_supported_generic_status_indicators %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
@@ -173,14 +173,14 @@ int hfp_hs_list_supported_generic_status_indicators_cmd(uint16_t cid){
 
 int hfp_hs_retrieve_supported_generic_status_indicators_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s=?\r\rn", HFP_Generic_Status_Indicator); 
+    sprintf(buffer, "AT%s=?\r\rn", HFP_GENERIC_STATUS_INDICATOR); 
     // printf("retrieve_supported_generic_status_indicators %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
 
 int hfp_hs_list_initital_supported_generic_status_indicators_cmd(uint16_t cid){
     char buffer[20];
-    sprintf(buffer, "AT%s?\r\n", HFP_Generic_Status_Indicator);
+    sprintf(buffer, "AT%s?\r\n", HFP_GENERIC_STATUS_INDICATOR);
     // printf("list_initital_supported_generic_status_indicators %s\n", buffer);
     return send_str_over_rfcomm(cid, buffer);
 }
@@ -378,8 +378,8 @@ hfp_connection_t * handle_message(hfp_connection_t * context, uint8_t *packet, u
         }
     }
 
-    if (strncmp((char *)packet, HFP_Supported_Features, strlen(HFP_Supported_Features)) == 0){
-        offset = strlen(HFP_Supported_Features) + 1; // +1 for =
+    if (strncmp((char *)packet, HFP_SUPPORTED_FEATURES, strlen(HFP_SUPPORTED_FEATURES)) == 0){
+        offset = strlen(HFP_SUPPORTED_FEATURES) + 1; // +1 for =
         context->remote_supported_features = atoi((char*)&packet[offset]);
         int i = 0;
         for (i=0; i<16; i++){
@@ -392,8 +392,8 @@ hfp_connection_t * handle_message(hfp_connection_t * context, uint8_t *packet, u
         return context;
     }
 
-    if (strncmp((char *)packet, HFP_Indicator, strlen(HFP_Indicator)) == 0){
-        offset = strlen(HFP_Indicator) + 1;
+    if (strncmp((char *)packet, HFP_INDICATOR, strlen(HFP_INDICATOR)) == 0){
+        offset = strlen(HFP_INDICATOR) + 1;
         switch (context->state){
             case HFP_W4_RETRIEVE_INDICATORS:
                 hfp_parse_indicators(context, &packet[offset], size-offset);
@@ -411,21 +411,21 @@ hfp_connection_t * handle_message(hfp_connection_t * context, uint8_t *packet, u
         return context;
     }
 
-    if (strncmp((char *)packet, HFP_Support_Call_Hold_And_Multiparty_Services, strlen(HFP_Support_Call_Hold_And_Multiparty_Services)) == 0){
-        offset = strlen(HFP_Support_Call_Hold_And_Multiparty_Services) + 1; // +1 for =
+    if (strncmp((char *)packet, HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES, strlen(HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES)) == 0){
+        offset = strlen(HFP_SUPPORT_CALL_HOLD_AND_MULTIPARTY_SERVICES) + 1; // +1 for =
         hfp_parse_comma_separated_tuple(context, &packet[offset], size-offset);
         context->state = HFP_LIST_GENERIC_STATUS_INDICATORS;
         context->wait_ok = 1;
         return context;
     } 
 
-    if (strncmp((char *)packet, HFP_Generic_Status_Indicator, strlen(HFP_Generic_Status_Indicator)) == 0){
+    if (strncmp((char *)packet, HFP_GENERIC_STATUS_INDICATOR, strlen(HFP_GENERIC_STATUS_INDICATOR)) == 0){
         // https://www.bluetooth.org/en-us/specification/assigned-numbers/hands-free-profile
         /* HF Indicators
          * 0x01 Enhanced Safety​, on/off
          * 0x02 Battery Level,   0-100
          */
-        offset = strlen(HFP_Generic_Status_Indicator) + 1; // +1 for =
+        offset = strlen(HFP_GENERIC_STATUS_INDICATOR) + 1; // +1 for =
                 
         switch (context->state){
             case HFP_W4_RETRIEVE_GENERIC_STATUS_INDICATORS:
diff --git a/test/pts/hfp_hf_test.c b/test/pts/hfp_hf_test.c
index b527850c4..e87da8c98 100644
--- a/test/pts/hfp_hf_test.c
+++ b/test/pts/hfp_hf_test.c
@@ -126,13 +126,13 @@ void packet_handler(uint8_t * event, uint16_t event_size){
 
 int btstack_main(int argc, const char * argv[]){
     // init L2CAP
-    uint8_t codecs[1] = {HFP_Codec_CVSD};
+    uint8_t codecs[1] = {HFP_CODEC_CVSD};
     uint16_t indicators[1] = {0x01};
 
     l2cap_init();
     rfcomm_init();
     
-    // hfp_hf_init(rfcomm_channel_nr, HFP_Default_HF_Supported_Features, codecs, sizeof(codecs), indicators, sizeof(indicators)/sizeof(uint16_t), 1);
+    // hfp_hf_init(rfcomm_channel_nr, HFP_DEFAULT_HF_SUPPORTED_FEATURES, codecs, sizeof(codecs), indicators, sizeof(indicators)/sizeof(uint16_t), 1);
     hfp_hf_init(rfcomm_channel_nr, 182, codecs, sizeof(codecs), indicators, sizeof(indicators)/sizeof(uint16_t), 1);
 
     hfp_register_packet_handler(packet_handler);