diff --git a/src/config_parser.c b/src/config_parser.c
index e79427db..0b53c590 100644
--- a/src/config_parser.c
+++ b/src/config_parser.c
@@ -931,7 +931,7 @@ static struct utun_config* parse_config_internal(FILE *fp, const char *filename)
                 break;
             case SECTION_ALLOWED_KEYS:
                 if (strcmp(key, "allow_all") == 0) {
-                    cfg->global.allowed_keys_allow_all = atoi(value) ? 1 : 0;
+                    cfg->global.allowed_keys_allow_all = strcasecmp(value, "yes") == 0 || strcasecmp(value, "1") == 0 || strcasecmp(value, "true") == 0;
                 } else if (strcmp(key, "key") == 0) {
                     struct CFG_ALLOWED_KEY *new_key = u_calloc(1, sizeof(struct CFG_ALLOWED_KEY));
                     if (!new_key) {