diff --git a/dmtree/tr181/wifi.c b/dmtree/tr181/wifi.c
index 0e2fe530..baf9bf67 100644
--- a/dmtree/tr181/wifi.c
+++ b/dmtree/tr181/wifi.c
@@ -720,9 +720,14 @@ static json_object *find_radio_object(json_object *device_obj, const char *uniqu
 		char mac[32] = {0};
 		char *id = dmjson_get_value(radio_obj, 1, "ID");
 		char *str = base64_decode(id);
-		string_to_mac(str, DM_STRLEN(str), mac, sizeof(mac));
-		if (DM_STRCMP(unique_key, mac) == 0)
-			return radio_obj;
+
+		/* Cant use strlen on byte array that might genuinely include 0x00 */
+		/* but to get 6 bytes, need 8 input BASE64 chars - check for that */
+		if ((str != NULL) && (DM_STRLEN(id) == 8)) {
+			string_to_mac(str, 6, mac, sizeof(mac));
+			if (DM_STRCMP(unique_key, mac) == 0)
+				return radio_obj;
+		}
 	}
 
 	return NULL;