diff --git a/lib/Hoymiles/src/parser/DevInfoParser.cpp b/lib/Hoymiles/src/parser/DevInfoParser.cpp
index 7d9251c..7c3c69d 100644
--- a/lib/Hoymiles/src/parser/DevInfoParser.cpp
+++ b/lib/Hoymiles/src/parser/DevInfoParser.cpp
@@ -108,8 +108,8 @@ uint32_t DevInfoParser::getHwPartNumber()
 
 String DevInfoParser::getHwVersion()
 {
-    char buf[6];
-    snprintf(buf, sizeof(buf), "%02X.%02X", _payloadDevInfoSimple[6], _payloadDevInfoSimple[7]);
+    char buf[8];
+    snprintf(buf, sizeof(buf), "%02d.%02d", _payloadDevInfoSimple[6], _payloadDevInfoSimple[7]);
     return String(buf);
 }