diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index ca9d035..4a1c047 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -759,7 +759,8 @@
 
 #endif /* SNI_OPTION */
 
-#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) || \
+    defined(MBEDTLS_SSL_CID)
 
 #define HEX2NUM( c )                    \
         if( c >= '0' && c <= '9' )      \
@@ -799,6 +800,10 @@
     return( 0 );
 }
 
+#endif
+
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
+
 typedef struct _psk_entry psk_entry;
 
 struct _psk_entry