diff --git a/desktop/sslcert_viewer.c b/desktop/sslcert_viewer.c
index 20b90bf6c..5280e094a 100644
--- a/desktop/sslcert_viewer.c
+++ b/desktop/sslcert_viewer.c
@@ -47,7 +47,7 @@ enum sslcert_viewer_field {
 
 /** ssl certificate verification context. */
 struct sslcert_session_data {
-	const struct ssl_cert_info *certs; /**< Certificates */
+	struct ssl_cert_info *certs; /**< Certificates */
 	unsigned long num;		/**< Number of certificates in chain */
 	nsurl *url;			/**< The url of the certificate */
 	llcache_query_response cb;	/**< Cert accept/reject callback */
@@ -394,8 +394,15 @@ static void sslcert_cleanup_session(struct sslcert_session_data *ssl_d)
 {
 	assert(ssl_d != NULL);
 
-	if (ssl_d->url)
+	if (ssl_d->url) {
 		nsurl_unref(ssl_d->url);
+		ssl_d->url = NULL;
+	}
+
+	if (ssl_d->certs) {
+		free(ssl_d->certs);
+		ssl_d->certs = NULL;
+	}
 
 	free(ssl_d);
 }
@@ -439,12 +446,19 @@ nserror sslcert_viewer_create_session_data(unsigned long num, nsurl *url,
 
 	data = malloc(sizeof(struct sslcert_session_data));
 	if (data == NULL) {
-		warn_user("NoMemory", 0);
 		*ssl_d = NULL;
 		return NSERROR_NOMEM;
 	}
 
-	data->certs = certs;
+	/* copy certificate data */
+	data->certs = malloc(num * sizeof(struct ssl_cert_info));
+	if (data->certs == NULL) {
+		free(data);
+		*ssl_d = NULL;
+		return NSERROR_NOMEM;
+	}
+	memcpy(data->certs, certs, num * sizeof(struct ssl_cert_info));
+
 	data->url = nsurl_ref(url);
 	data->num = num;
 	data->cb = cb;
diff --git a/gtk/gui.c b/gtk/gui.c
index bb83721fe..95e503af2 100644
--- a/gtk/gui.c
+++ b/gtk/gui.c
@@ -653,10 +653,18 @@ static void gui_cert_verify(nsurl *url, const struct ssl_cert_info *certs,
 	GError* error = NULL;
 	GtkBuilder* builder;
 
+	/* state while window is open */
+	session = calloc(sizeof(void *), 3);
+	if (session == NULL) {
+		return;
+	}
+
 	builder = gtk_builder_new ();
 	if (!gtk_builder_add_from_file(builder, glade_file_location->ssl, &error)) {
 		g_warning("Couldn't load builder file: %s", error->message);
 		g_error_free(error);
+
+		free(session);
 		return;
 	}
 
@@ -667,11 +675,6 @@ static void gui_cert_verify(nsurl *url, const struct ssl_cert_info *certs,
 	scrolled = GTK_SCROLLED_WINDOW(gtk_builder_get_object(builder, "SSLScrolled"));
 	drawing_area = GTK_DRAWING_AREA(gtk_builder_get_object(builder, "SSLDrawingArea"));
 
-	session = calloc(sizeof(void *), 3);
-
-	if (session == NULL) {
-		return;
-	}
 
 	ssl_window = nsgtk_treeview_create(TREE_SSLCERT, window, scrolled,
 			drawing_area);