diff --git a/sonoff/support.ino b/sonoff/support.ino
index 3198cf7cb..f49304884 100644
--- a/sonoff/support.ino
+++ b/sonoff/support.ino
@@ -1557,7 +1557,7 @@ void AddLogBuffer(uint32_t loglevel, uint8_t *buffer, uint32_t count)
   ToHex_P(buffer, count, log_data + strlen(log_data), sizeof(log_data) - strlen(log_data), ' ');
   AddLog(loglevel);
 */
-  char hex_char[count * 3];
+  char hex_char[(count * 3) + 2];
   AddLog_P2(loglevel, PSTR("DMP: %s"), ToHex_P(buffer, count, hex_char, sizeof(hex_char), ' '));
 }