diff --git a/CHANGELOG.md b/CHANGELOG.md
index c572cda42..73089e353 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ HEAD
 
 * Fixed error when assigning a `volatile int` to a `JsonVariant` (issue #415)
 * Fixed errors with Variable Length Arrays (issue #416)
+* Fixed error when both `ARDUINOJSON_ENABLE_STD_STREAM` and `ARDUINOJSON_ENABLE_ARDUINO_STREAM` are set to `1`
 
 v5.8.0
 ------
diff --git a/include/ArduinoJson/Data/ValueSetter.hpp b/include/ArduinoJson/Data/ValueSetter.hpp
index 07d3ddd68..3898a536f 100644
--- a/include/ArduinoJson/Data/ValueSetter.hpp
+++ b/include/ArduinoJson/Data/ValueSetter.hpp
@@ -26,8 +26,8 @@ struct ValueSetter {
 };
 
 template <typename TSource>
-struct ValueSetter<TSource, typename TypeTraits::EnableIf<
-                                StringFuncs<TSource>::should_duplicate>::type> {
+struct ValueSetter<TSource, typename TypeTraits::EnableIf<StringTraits<
+                                TSource>::should_duplicate>::type> {
   template <typename TDestination>
   static bool set(JsonBuffer* buffer, TDestination& destination,
                   const TSource& source) {
diff --git a/include/ArduinoJson/Deserialization/JsonParser.hpp b/include/ArduinoJson/Deserialization/JsonParser.hpp
index 65e064bee..676cdf8bc 100644
--- a/include/ArduinoJson/Deserialization/JsonParser.hpp
+++ b/include/ArduinoJson/Deserialization/JsonParser.hpp
@@ -74,7 +74,7 @@ class JsonParser {
 
 template <typename TJsonBuffer, typename TString>
 struct JsonParserBuilder {
-  typedef typename Internals::StringFuncs<TString>::Iterator InputIterator;
+  typedef typename Internals::StringTraits<TString>::Iterator InputIterator;
   typedef JsonParser<StringReader<InputIterator>, TJsonBuffer &> TParser;
 
   static TParser makeParser(TJsonBuffer *buffer, TString &json,
@@ -85,7 +85,7 @@ struct JsonParserBuilder {
 
 template <typename TJsonBuffer>
 struct JsonParserBuilder<TJsonBuffer, char *> {
-  typedef typename Internals::StringFuncs<char *>::Iterator InputIterator;
+  typedef typename Internals::StringTraits<char *>::Iterator InputIterator;
   typedef JsonParser<StringReader<InputIterator>, StringWriter> TParser;
 
   static TParser makeParser(TJsonBuffer *buffer, char *json,
diff --git a/include/ArduinoJson/JsonBuffer.hpp b/include/ArduinoJson/JsonBuffer.hpp
index e1c787741..30b18a2eb 100644
--- a/include/ArduinoJson/JsonBuffer.hpp
+++ b/include/ArduinoJson/JsonBuffer.hpp
@@ -61,14 +61,14 @@ class JsonBuffer {
   typename TypeTraits::EnableIf<!TypeTraits::IsArray<TString>::value,
                                 char *>::type
   strdup(const TString &src) {
-    return Internals::StringFuncs<TString>::duplicate(src, this);
+    return Internals::StringTraits<TString>::duplicate(src, this);
   }
   //
   // char* strdup(TValue);
   // TValue = const char*, const char[N], const FlashStringHelper*
   template <typename TString>
   char *strdup(const TString *src) {
-    return Internals::StringFuncs<const TString *>::duplicate(src, this);
+    return Internals::StringTraits<const TString *>::duplicate(src, this);
   }
 
   // Allocates n bytes in the JsonBuffer.
diff --git a/include/ArduinoJson/JsonObject.hpp b/include/ArduinoJson/JsonObject.hpp
index 873289fef..47202a1df 100644
--- a/include/ArduinoJson/JsonObject.hpp
+++ b/include/ArduinoJson/JsonObject.hpp
@@ -282,7 +282,7 @@ class JsonObject : public Internals::JsonPrintable<JsonObject>,
   template <typename TStringRef>
   node_type* findNode(TStringRef key) const {
     for (node_type* node = _firstNode; node; node = node->next) {
-      if (Internals::StringFuncs<TStringRef>::equals(key, node->content.key))
+      if (Internals::StringTraits<TStringRef>::equals(key, node->content.key))
         return node;
     }
     return NULL;
diff --git a/include/ArduinoJson/JsonVariant.hpp b/include/ArduinoJson/JsonVariant.hpp
index 43d012548..6a066045e 100644
--- a/include/ArduinoJson/JsonVariant.hpp
+++ b/include/ArduinoJson/JsonVariant.hpp
@@ -163,7 +163,7 @@ class JsonVariant : public JsonVariantBase<JsonVariant> {
   // std::string as<std::string>() const;
   // String as<String>() const;
   template <typename T>
-  typename TypeTraits::EnableIf<Internals::StringFuncs<T>::has_append, T>::type
+  typename TypeTraits::EnableIf<Internals::StringTraits<T>::has_append, T>::type
   as() const {
     const char *cstr = asString();
     if (cstr) return T(cstr);
diff --git a/include/ArduinoJson/JsonVariantBase.hpp b/include/ArduinoJson/JsonVariantBase.hpp
index 7c9a9e5e8..22cb91143 100644
--- a/include/ArduinoJson/JsonVariantBase.hpp
+++ b/include/ArduinoJson/JsonVariantBase.hpp
@@ -83,7 +83,7 @@ class JsonVariantBase : public Internals::JsonPrintable<TImpl> {
   // TKey = const std::string&, const String&
   template <typename TString>
   FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringFuncs<TString>::has_equals,
+      Internals::StringTraits<TString>::has_equals,
       const JsonObjectSubscript<const TString &> >::type
   operator[](const TString &key) const {
     return asObject()[key];
@@ -92,10 +92,10 @@ class JsonVariantBase : public Internals::JsonPrintable<TImpl> {
   // const JsonObjectSubscript operator[](TKey) const;
   // TKey = const char*, const char[N], const FlashStringHelper*
   template <typename TString>
-  FORCE_INLINE
-      typename TypeTraits::EnableIf<Internals::StringFuncs<TString>::has_equals,
-                                    JsonObjectSubscript<const TString &> >::type
-      operator[](const TString &key) {
+  FORCE_INLINE typename TypeTraits::EnableIf<
+      Internals::StringTraits<TString>::has_equals,
+      JsonObjectSubscript<const TString &> >::type
+  operator[](const TString &key) {
     return asObject()[key];
   }
   //
@@ -103,7 +103,7 @@ class JsonVariantBase : public Internals::JsonPrintable<TImpl> {
   // TKey = const std::string&, const String&
   template <typename TString>
   FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringFuncs<TString *>::has_equals,
+      Internals::StringTraits<TString *>::has_equals,
       JsonObjectSubscript<const TString *> >::type
   operator[](const TString *key) {
     return asObject()[key];
@@ -113,7 +113,7 @@ class JsonVariantBase : public Internals::JsonPrintable<TImpl> {
   // TKey = const char*, const char[N], const FlashStringHelper*
   template <typename TString>
   FORCE_INLINE typename TypeTraits::EnableIf<
-      Internals::StringFuncs<TString *>::has_equals,
+      Internals::StringTraits<TString *>::has_equals,
       const JsonObjectSubscript<const TString *> >::type
   operator[](const TString *key) const {
     return asObject()[key];
diff --git a/include/ArduinoJson/JsonVariantComparisons.hpp b/include/ArduinoJson/JsonVariantComparisons.hpp
index 8af2f780b..590670e37 100644
--- a/include/ArduinoJson/JsonVariantComparisons.hpp
+++ b/include/ArduinoJson/JsonVariantComparisons.hpp
@@ -21,11 +21,11 @@ struct JsonVariantComparer {
 
 template <typename TVariant, typename TString>
 struct JsonVariantComparer<
-    TVariant, TString, typename TypeTraits::EnableIf<
-                           Internals::StringFuncs<TString>::has_equals>::type> {
+    TVariant, TString, typename TypeTraits::EnableIf<Internals::StringTraits<
+                           TString>::has_equals>::type> {
   static bool equals(const TVariant &variant, const TString &comparand) {
     const char *value = variant.template as<const char *>();
-    return Internals::StringFuncs<TString>::equals(comparand, value);
+    return Internals::StringTraits<TString>::equals(comparand, value);
   }
 };
 
diff --git a/include/ArduinoJson/Serialization/DynamicStringBuilder.hpp b/include/ArduinoJson/Serialization/DynamicStringBuilder.hpp
index 56a935f20..dc520d13d 100644
--- a/include/ArduinoJson/Serialization/DynamicStringBuilder.hpp
+++ b/include/ArduinoJson/Serialization/DynamicStringBuilder.hpp
@@ -20,7 +20,7 @@ class DynamicStringBuilder : public Print {
   DynamicStringBuilder(TString &str) : _str(str) {}
 
   virtual size_t write(uint8_t c) {
-    StringFuncs<TString>::append(_str, static_cast<char>(c));
+    StringTraits<TString>::append(_str, static_cast<char>(c));
     return 1;
   }
 
diff --git a/include/ArduinoJson/Serialization/JsonPrintable.hpp b/include/ArduinoJson/Serialization/JsonPrintable.hpp
index fba1ce140..3e17fd5cc 100644
--- a/include/ArduinoJson/Serialization/JsonPrintable.hpp
+++ b/include/ArduinoJson/Serialization/JsonPrintable.hpp
@@ -56,7 +56,7 @@ class JsonPrintable {
   }
 
   template <typename TString>
-  typename TypeTraits::EnableIf<StringFuncs<TString>::has_append, size_t>::type
+  typename TypeTraits::EnableIf<StringTraits<TString>::has_append, size_t>::type
   printTo(TString &str) const {
     DynamicStringBuilder<TString> sb(str);
     return printTo(sb);
@@ -83,7 +83,7 @@ class JsonPrintable {
   }
 
   template <typename TString>
-  typename TypeTraits::EnableIf<StringFuncs<TString>::has_append, size_t>::type
+  typename TypeTraits::EnableIf<StringTraits<TString>::has_append, size_t>::type
   prettyPrintTo(TString &str) const {
     DynamicStringBuilder<TString> sb(str);
     return prettyPrintTo(sb);
diff --git a/include/ArduinoJson/StringTraits/ArduinoStream.hpp b/include/ArduinoJson/StringTraits/ArduinoStream.hpp
index de66bc353..857fe8eb8 100644
--- a/include/ArduinoJson/StringTraits/ArduinoStream.hpp
+++ b/include/ArduinoJson/StringTraits/ArduinoStream.hpp
@@ -14,7 +14,7 @@
 namespace ArduinoJson {
 namespace Internals {
 
-struct StdStreamFuncs {
+struct ArduinoStreamTraits {
   class Iterator {
     Stream& _stream;
 
@@ -29,11 +29,11 @@ struct StdStreamFuncs {
 };
 
 template <typename TStream>
-struct StringFuncs<TStream,
-                   // match any type that is derived from std::istream:
-                   typename TypeTraits::EnableIf<TypeTraits::IsBaseOf<
-                       Stream, typename TypeTraits::RemoveReference<
-                                   TStream>::type>::value>::type>
-    : StdStreamFuncs {};
+struct StringTraits<TStream,
+                    // match any type that is derived from Stream:
+                    typename TypeTraits::EnableIf<TypeTraits::IsBaseOf<
+                        Stream, typename TypeTraits::RemoveReference<
+                                    TStream>::type>::value>::type>
+    : ArduinoStreamTraits {};
 }
 }
diff --git a/include/ArduinoJson/StringTraits/CharPointer.hpp b/include/ArduinoJson/StringTraits/CharPointer.hpp
index d04c5f71c..e5d0efff0 100644
--- a/include/ArduinoJson/StringTraits/CharPointer.hpp
+++ b/include/ArduinoJson/StringTraits/CharPointer.hpp
@@ -10,7 +10,7 @@
 namespace ArduinoJson {
 namespace Internals {
 
-struct CharPtrFuncs {
+struct CharPointerTraits {
   class Iterator {
     const char* _ptr;
 
@@ -43,9 +43,9 @@ struct CharPtrFuncs {
 };
 
 template <>
-struct StringFuncs<const char*, void> : CharPtrFuncs {};
+struct StringTraits<const char*, void> : CharPointerTraits {};
 
 template <>
-struct StringFuncs<char*, void> : CharPtrFuncs {};
+struct StringTraits<char*, void> : CharPointerTraits {};
 }
 }
diff --git a/include/ArduinoJson/StringTraits/FlashString.hpp b/include/ArduinoJson/StringTraits/FlashString.hpp
index 82711633b..6c44ee97c 100644
--- a/include/ArduinoJson/StringTraits/FlashString.hpp
+++ b/include/ArduinoJson/StringTraits/FlashString.hpp
@@ -10,7 +10,7 @@
 namespace ArduinoJson {
 namespace Internals {
 template <>
-struct StringFuncs<const __FlashStringHelper*, void> {
+struct StringTraits<const __FlashStringHelper*, void> {
   class Iterator {
     const char* _ptr;
 
diff --git a/include/ArduinoJson/StringTraits/StdStream.hpp b/include/ArduinoJson/StringTraits/StdStream.hpp
index 38f7954bb..d3614cd1c 100644
--- a/include/ArduinoJson/StringTraits/StdStream.hpp
+++ b/include/ArduinoJson/StringTraits/StdStream.hpp
@@ -15,7 +15,7 @@
 namespace ArduinoJson {
 namespace Internals {
 
-struct StdStreamFuncs {
+struct StdStreamTraits {
   class Iterator {
     std::istream& _stream;
 
@@ -32,11 +32,11 @@ struct StdStreamFuncs {
 };
 
 template <typename TStream>
-struct StringFuncs<TStream,
-                   // match any type that is derived from std::istream:
-                   typename TypeTraits::EnableIf<TypeTraits::IsBaseOf<
-                       std::istream, typename TypeTraits::RemoveReference<
-                                         TStream>::type>::value>::type>
-    : StdStreamFuncs {};
+struct StringTraits<TStream,
+                    // match any type that is derived from std::istream:
+                    typename TypeTraits::EnableIf<TypeTraits::IsBaseOf<
+                        std::istream, typename TypeTraits::RemoveReference<
+                                          TStream>::type>::value>::type>
+    : StdStreamTraits {};
 }
 }
diff --git a/include/ArduinoJson/StringTraits/StdString.hpp b/include/ArduinoJson/StringTraits/StdString.hpp
index cfb848cf9..1d206c7f5 100644
--- a/include/ArduinoJson/StringTraits/StdString.hpp
+++ b/include/ArduinoJson/StringTraits/StdString.hpp
@@ -19,7 +19,7 @@ namespace ArduinoJson {
 namespace Internals {
 
 template <typename TString>
-struct StdStringFuncs {
+struct StdStringTraits {
   template <typename Buffer>
   static char* duplicate(const TString& str, Buffer* buffer) {
     if (!str.c_str()) return NULL;  // <- Arduino string can return NULL
@@ -29,8 +29,8 @@ struct StdStringFuncs {
     return static_cast<char*>(dup);
   }
 
-  struct Iterator : CharPtrFuncs::Iterator {
-    Iterator(const TString& str) : CharPtrFuncs::Iterator(str.c_str()) {}
+  struct Iterator : CharPointerTraits::Iterator {
+    Iterator(const TString& str) : CharPointerTraits::Iterator(str.c_str()) {}
   };
 
   static bool equals(const TString& str, const char* expected) {
@@ -48,14 +48,15 @@ struct StdStringFuncs {
 
 #if ARDUINOJSON_ENABLE_ARDUINO_STRING
 template <>
-struct StringFuncs<String, void> : StdStringFuncs<String> {};
+struct StringTraits<String, void> : StdStringTraits<String> {};
 template <>
-struct StringFuncs<StringSumHelper, void> : StdStringFuncs<StringSumHelper> {};
+struct StringTraits<StringSumHelper, void> : StdStringTraits<StringSumHelper> {
+};
 #endif
 
 #if ARDUINOJSON_ENABLE_STD_STRING
 template <>
-struct StringFuncs<std::string, void> : StdStringFuncs<std::string> {};
+struct StringTraits<std::string, void> : StdStringTraits<std::string> {};
 #endif
 }
 }
diff --git a/include/ArduinoJson/StringTraits/StringTraits.hpp b/include/ArduinoJson/StringTraits/StringTraits.hpp
index b4f23e848..3f0b63f27 100644
--- a/include/ArduinoJson/StringTraits/StringTraits.hpp
+++ b/include/ArduinoJson/StringTraits/StringTraits.hpp
@@ -13,13 +13,13 @@ namespace ArduinoJson {
 namespace Internals {
 
 template <typename TString, typename Enable = void>
-struct StringFuncs {};
+struct StringTraits {};
 
 template <typename TString>
-struct StringFuncs<const TString, void> : StringFuncs<TString> {};
+struct StringTraits<const TString, void> : StringTraits<TString> {};
 
 template <typename TString>
-struct StringFuncs<TString&, void> : StringFuncs<TString> {};
+struct StringTraits<TString&, void> : StringTraits<TString> {};
 }
 }