diff --git a/src/cluster.c b/src/cluster.c
index ced7668d65..566ac5a19e 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -748,7 +748,16 @@ int verifyClusterNodeId(const char *name, int length) {
 }
 
 int isValidAuxChar(int c) {
-    return isalnum(c) || (strchr("!#$%&()*+.:;<>?@[]^{|}~", c) == NULL);
+    /* Return true if the character is alphanumeric */
+    if (isalnum(c)) {
+        return 1;
+    }
+
+    /* List of invalid characters */
+    static const char *invalid_charset = "!#$%&()*+;<>?@[]^{|}~";
+
+    /* Return true if the character is NOT in the invalid charset */
+    return strchr(invalid_charset, c) == NULL;
 }
 
 int isValidAuxString(char *s, unsigned int length) {
diff --git a/tests/unit/cluster/announce-client-ip.tcl b/tests/unit/cluster/announce-client-ip.tcl
index f0aebd0807..68d13f821a 100644
--- a/tests/unit/cluster/announce-client-ip.tcl
+++ b/tests/unit/cluster/announce-client-ip.tcl
@@ -147,3 +147,17 @@ start_cluster 2 2 {tags {external:skip cluster ipv6} overrides {cluster-replica-
         [lindex $clients $j] close
     }
 }
+
+start_cluster 1 0 {tags {external:skip cluster} overrides {cluster-replica-no-failover yes bind {127.0.0.1 ::1}}} {
+    test "Load cluster announced IPv4 config on server start" {
+        R 0 config set cluster-announce-client-ipv4 "1.1.1.1"
+        restart_server 0 true false
+    }
+}
+
+start_cluster 1 0 {tags {external:skip cluster ipv6} overrides {cluster-replica-no-failover yes bind {127.0.0.1 ::1}}} {
+    test "Load cluster announced IPv6 config on server start" {
+        R 0 config set cluster-announce-client-ipv6 "cafe:1234::0"
+        restart_server 0 true false
+    }
+}