diff --git a/src/config.c b/src/config.c
index 3f40c7ae..0dcffdcf 100644
--- a/src/config.c
+++ b/src/config.c
@@ -934,56 +934,57 @@ int read_config(struct booth_config **conf, const char *path, int type)
 	return -1;
 }
 
-
-int check_config(int type)
+int check_config(struct booth_config *conf, int type)
 {
 	struct passwd *pw;
 	struct group *gr;
 	char *cp, *input;
 
-	if (!booth_conf)
+	if (conf == NULL) {
 		return -1;
-
+	}
 
 	input = (type == ARBITRATOR)
-		? booth_conf->arb_user
-		: booth_conf->site_user;
+		? conf->arb_user
+		: conf->site_user;
 	if (!*input)
 		goto u_inval;
 	if (isdigit(input[0])) {
-		booth_conf->uid = strtol(input, &cp, 0);
+		conf->uid = strtol(input, &cp, 0);
 		if (*cp != 0) {
 u_inval:
 			log_error("User \"%s\" cannot be resolved into a UID.", input);
 			return ENOENT;
 		}
-	}
-	else {
+	} else {
 		pw = getpwnam(input);
 		if (!pw)
 			goto u_inval;
-		booth_conf->uid = pw->pw_uid;
+		conf->uid = pw->pw_uid;
 	}
 
 
 	input = (type == ARBITRATOR)
-		? booth_conf->arb_group
-		: booth_conf->site_group;
-	if (!*input)
+		? conf->arb_group
+		: conf->site_group;
+
+	if (!*input) {
 		goto g_inval;
+	}
+
 	if (isdigit(input[0])) {
-		booth_conf->gid = strtol(input, &cp, 0);
+		conf->gid = strtol(input, &cp, 0);
 		if (*cp != 0) {
 g_inval:
 			log_error("Group \"%s\" cannot be resolved into a UID.", input);
 			return ENOENT;
 		}
-	}
-	else {
+	} else {
 		gr = getgrnam(input);
-		if (!gr)
+		if (!gr) {
 			goto g_inval;
-		booth_conf->gid = gr->gr_gid;
+		}
+		conf->gid = gr->gr_gid;
 	}
 
 	return 0;
diff --git a/src/config.h b/src/config.h
index 0ee0ea5e..220b4f0f 100644
--- a/src/config.h
+++ b/src/config.h
@@ -339,7 +339,19 @@ extern struct booth_config *booth_conf;
  */
 int read_config(struct booth_config **conf, const char *path, int type);
 
-int check_config(int type);
+/**
+ * @internal
+ * Check booth configuration
+ *
+ * Currently it means checking that login user/group indeed exists,
+ * while converting it to respective numeric values for further use.
+ *
+ * @param[in,out] conf_ptr config object to check
+ * @param[in] type role currently being acted as
+ *
+ * @return 0 or negative value (-1 or -errno) on error
+ */
+int check_config(struct booth_config *conf, int type);
 
 int find_site_by_name(char *site, struct booth_site **node, int any_type);
 int find_site_by_id(uint32_t site_id, struct booth_site **node);
diff --git a/src/main.c b/src/main.c
index 8a762049..3ad0290f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -404,7 +404,7 @@ static int setup_config(struct booth_config **conf, int type)
 		find_myself(NULL, type == CLIENT || type == GEOSTORE);
 
 
-	rv = check_config(type);
+	rv = check_config(booth_conf, type);
 	if (rv < 0)
 		goto out;