diff --git a/generator.c b/generator.c
index eee653b..74980a2 100644
--- a/generator.c
+++ b/generator.c
@@ -85,10 +85,11 @@ int strToInt(char *str)
 	char *endptr;
 	long val;
 
+	errno = 0;
 	val = strtol(str, &endptr, 10);
 	if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN)) ||
 	    (errno != 0)) {
-		perror(pname);
+		perror("[./generator] strtol");
 		return -2;
 	}
 	if (val < INT_MIN || val > INT_MAX) {
@@ -314,7 +315,7 @@ int main(int argc, char *argv[])
 	sigaction(SIGINT, &sa, NULL);
 	sigaction(SIGTERM, &sa, NULL);
 
-	shmfd = shm_open(SHM_NAME, O_RDWR | O_CREAT, PERMISSION);
+	shmfd = shm_open(SHM_NAME, O_RDWR, PERMISSION);
 	if (shmfd == -1) {
 		perror("[./generator] shm_open");
 		exit(EXIT_FAILURE);