diff --git a/lib/ext/wocky/wocky/wocky-sasl-scram.c b/lib/ext/wocky/wocky/wocky-sasl-scram.c
index 7261956..c508196 100644
--- a/lib/ext/wocky/wocky/wocky-sasl-scram.c
+++ b/lib/ext/wocky/wocky/wocky-sasl-scram.c
@@ -523,7 +523,7 @@ scram_handle_server_final_message (WockySaslScram *self,
     gchar *message,
     GError **error)
 {
-  gchar attr, *value = NULL;
+  gchar attr = 0, *value = NULL;
 
   if (!scram_get_next_attr_value (&message, &attr, &value) && attr != 'v')
     goto invalid;