diff --git a/src/trace.cpp b/src/trace.cpp
index 896dbaa..653e50e 100644
--- a/src/trace.cpp
+++ b/src/trace.cpp
@@ -109,7 +109,15 @@ static String _getText(const char *buffer)
     break;
 
     default:
-      res.concat(*buffer);
+      if (*buffer < 128)
+        res.concat(*buffer);
+      else
+      {
+        char chr[3];
+        res.concat(F("\\u00"));
+        sprintf_P(chr, PSTR("%02X"), *buffer);
+        res.concat(chr);
+      }
     break;
     }
     ++buffer;