Remove peer CRT from mbedtls_ssl_session if !KEEP_PEER_CERT
diff --git a/include/mbedtls/ssl_cache.h b/include/mbedtls/ssl_cache.h
index 52ba094..84254d3 100644
--- a/include/mbedtls/ssl_cache.h
+++ b/include/mbedtls/ssl_cache.h
@@ -70,7 +70,8 @@
     mbedtls_time_t timestamp;           /*!< entry timestamp    */
 #endif
     mbedtls_ssl_session session;        /*!< entry session      */
-#if defined(MBEDTLS_X509_CRT_PARSE_C)
+#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
+    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
     mbedtls_x509_buf peer_cert;         /*!< entry peer_cert    */
 #endif
     mbedtls_ssl_cache_entry *next;      /*!< chain pointer      */