diff --git a/src/main.h b/src/main.h
index bc47193..b0e0b46 100644
--- a/src/main.h
+++ b/src/main.h
@@ -13,8 +13,8 @@
 // Using CRELAY_ prefix to avoid conflicts with nostr_core_lib VERSION macros
 #define CRELAY_VERSION_MAJOR 1
 #define CRELAY_VERSION_MINOR 2
-#define CRELAY_VERSION_PATCH 3
-#define CRELAY_VERSION "v1.2.3"
+#define CRELAY_VERSION_PATCH 4
+#define CRELAY_VERSION "v1.2.4"
 
 // Relay metadata (authoritative source for NIP-11 information)
 #define RELAY_NAME "C-Relay"
diff --git a/src/subscriptions.c b/src/subscriptions.c
index 4755af0..8a40e64 100644
--- a/src/subscriptions.c
+++ b/src/subscriptions.c
@@ -266,10 +266,13 @@ int validate_subscription_id(const char* sub_id) {
     }
 
     // Check for valid characters (alphanumeric, underscore, hyphen, colon, comma, plus)
+    // Plus URL-safe special characters: ! $ % & ( ) * . = ? @ # ~
     for (size_t i = 0; i < len; i++) {
         char c = sub_id[i];
         if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
-              (c >= '0' && c <= '9') || c == '_' || c == '-' || c == ':' || c == ',' || c == '+')) {
+              (c >= '0' && c <= '9') || c == '_' || c == '-' || c == ':' || c == ',' || c == '+' ||
+              c == '!' || c == '$' || c == '%' || c == '&' || c == '(' || c == ')' ||
+              c == '*' || c == '.' || c == '=' || c == '?' || c == '@' || c == '#' || c == '~')) {
             return 0; // Invalid character
         }
     }