diff --git a/src/snprintf.c b/src/snprintf.c
index e018edb..3e854e5 100644
--- a/src/snprintf.c
+++ b/src/snprintf.c
@@ -705,7 +705,7 @@ static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c)
 
 int xmpp_vsnprintf (char *str, size_t count, const char *fmt, va_list args)
 {
-  if (str != NULL)
+  if (str != NULL && count > 0)
     str[0] = 0;
   return dopr(str, count, fmt, args);
 }
diff --git a/src/stanza.c b/src/stanza.c
index 38af9ac..036f478 100644
--- a/src/stanza.c
+++ b/src/stanza.c
@@ -291,7 +291,7 @@ static inline void _render_update(int *written, const int length,
 {
     *written += lastwrite;
 
-    if (*written > length) {
+    if (*written >= length) {
 	*left = 0;
 	*ptr = NULL;
     } else {