diff --git a/CHANGELOG.md b/CHANGELOG.md
index e039c842..69f2836c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ HEAD
 * Fix double lookup in `to<JsonVariant>()`
 * Fix double call to `size()` in `serializeMsgPack()`
 * Include `ARDUINOJSON_SLOT_OFFSET_SIZE` in the namespace name
+* Show a link to the documentation when user passes an unsupported input type
 
 v6.21.2 (2023-04-12)
 -------
diff --git a/src/ArduinoJson/Deserialization/Reader.hpp b/src/ArduinoJson/Deserialization/Reader.hpp
index 5f18c7b3..44437686 100644
--- a/src/ArduinoJson/Deserialization/Reader.hpp
+++ b/src/ArduinoJson/Deserialization/Reader.hpp
@@ -18,7 +18,9 @@ struct Reader {
   Reader(TSource& source) : source_(&source) {}
 
   int read() {
-    return source_->read();  // Error here? You passed an unsupported input type
+    // clang-format off
+    return source_->read();  // Error here? See https://arduinojson.org/v6/invalid-input/
+    // clang-format on
   }
 
   size_t readBytes(char* buffer, size_t length) {