diff --git a/src/classic/hfp_hf.c b/src/classic/hfp_hf.c
index 4268ddd69..e7cab862d 100644
--- a/src/classic/hfp_hf.c
+++ b/src/classic/hfp_hf.c
@@ -117,7 +117,7 @@ static void hfp_hf_emit_subscriber_information(btstack_packet_handler_t callback
     event[2] = event_subtype;
     event[3] = status;
     event[4] = bnip_type;
-    int size = (strlen(bnip_number) < (sizeof(event) - 6)) ? (int) strlen(bnip_number) : ((int) sizeof(event) - 6);
+    uint16_t size = btstack_min(strlen(bnip_number), sizeof(event) - 6);
     strncpy((char*)&event[5], bnip_number, size);
     event[5 + size] = 0;
     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
@@ -130,7 +130,7 @@ static void hfp_hf_emit_type_and_number(btstack_packet_handler_t callback, uint8
     event[1] = sizeof(event) - 2;
     event[2] = event_subtype;
     event[3] = bnip_type;
-    int size = (strlen(bnip_number) < (sizeof(event) - 5)) ? (int) strlen(bnip_number) : ((int) sizeof(event) - 5);
+    uint16_t size = btstack_min(strlen(bnip_number), sizeof(event) - 5);
     strncpy((char*)&event[4], bnip_number, size);
     event[4 + size] = 0;
     (*callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
@@ -151,7 +151,7 @@ static void hfp_hf_emit_enhanced_call_status(btstack_packet_handler_t callback,
     event[pos++] = clcc_mode;
     event[pos++] = clcc_mpty;
     event[pos++] = bnip_type;
-    int size = (strlen(bnip_number) < (sizeof(event) - pos)) ? (int) strlen(bnip_number) : ((int) sizeof(event) - pos);
+    uint16_t size = btstack_min(strlen(bnip_number), sizeof(event) - pos);
     strncpy((char*)&event[pos], bnip_number, size);
     pos += size;
     event[pos++] = 0;