diff --git a/src/first-free-port.c b/src/first-free-port.c
index c823684..1e246cd 100644
--- a/src/first-free-port.c
+++ b/src/first-free-port.c
@@ -81,14 +81,14 @@ int main(int argc, char *argv[]) {
     }
 
     if (!is_valid_tcp_port(current_port)) {
-        fprintf(stderr, "Provide a valid TCP port number as first argument.\n");
+        fprintf(stderr, "%s: provide a valid TCP port number as first argument.\n", argv[0]);
         return EX_USAGE;
     }
 
     // Open TCP table
     FILE *tcp_table_fptr = fopen(TCP_TABLE, "r");
     if (tcp_table_fptr == NULL) {
-        fprintf(stderr, "Error opening the TCP table.\n");
+        fprintf(stderr, "%s: error opening the TCP table.\n", argv[0]);
         return EX_OSFILE;
     }
 
@@ -106,7 +106,7 @@ int main(int argc, char *argv[]) {
         printf("%d\n", current_port);
         return EXIT_SUCCESS;
     } else {
-        fprintf(stderr, "No more ports available. How did you fuck up that bad ???\n");
+        fprintf(stderr, "%s: no more ports available; how did you fuck up that bad ???\n", argv[0]);
         return EX_TEMPFAIL;
     }
 }