diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2d2d47c..ea513b2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ ArduinoJson: change log
 v5.0.3
 ------
 
-* Nothing yet.
+* Fixed `printTo(String)` which wrote numbers instead of strings (issue #120)
 
 v5.0.2
 ------
diff --git a/include/ArduinoJson/Internals/DynamicStringBuilder.hpp b/include/ArduinoJson/Internals/DynamicStringBuilder.hpp
index 255b6671..e5595982 100644
--- a/include/ArduinoJson/Internals/DynamicStringBuilder.hpp
+++ b/include/ArduinoJson/Internals/DynamicStringBuilder.hpp
@@ -18,7 +18,8 @@ class DynamicStringBuilder : public Print {
   DynamicStringBuilder(String &str) : _str(str) {}
 
   virtual size_t write(uint8_t c) {
-    _str += c;
+    // Need to cast to char, otherwise String will print a number (issue #120)
+    _str += static_cast<char>(c);
     return 1;
   }