diff --git a/src/ArduinoJson/Memory/MemoryPool.hpp b/src/ArduinoJson/Memory/MemoryPool.hpp
index c8262186..7d3cd0c6 100644
--- a/src/ArduinoJson/Memory/MemoryPool.hpp
+++ b/src/ArduinoJson/Memory/MemoryPool.hpp
@@ -7,6 +7,7 @@
 #include <ArduinoJson/Memory/Alignment.hpp>
 #include <ArduinoJson/Polyfills/assert.hpp>
 #include <ArduinoJson/Polyfills/mpl/max.hpp>
+#include <ArduinoJson/Strings/StringAdapters.hpp>
 #include <ArduinoJson/Variant/VariantSlot.hpp>
 
 #include <string.h>  // memmove
@@ -64,7 +65,7 @@ class MemoryPool {
       return 0;
 
 #if ARDUINOJSON_ENABLE_STRING_DEDUPLICATION
-    const char* existingCopy = findString(str.begin());
+    const char* existingCopy = findString(str);
     if (existingCopy)
       return existingCopy;
 #endif
@@ -86,7 +87,7 @@ class MemoryPool {
 
   const char* saveStringFromFreeZone(size_t len) {
 #if ARDUINOJSON_ENABLE_STRING_DEDUPLICATION
-    const char* dup = findString(_left);
+    const char* dup = findString(adaptString(_left));
     if (dup)
       return dup;
 #endif
@@ -163,16 +164,11 @@ class MemoryPool {
   }
 
 #if ARDUINOJSON_ENABLE_STRING_DEDUPLICATION
-  template <typename TIterator>
-  const char* findString(TIterator str) {
+  template <typename TAdaptedString>
+  const char* findString(const TAdaptedString& str) {
     for (char* next = _begin; next < _left; ++next) {
-      char* begin = next;
-
-      // try to match
-      for (TIterator it = str; *it == *next; ++it) {
-        if (*next++ == 0)
-          return begin;
-      }
+      if (str.equals(next))
+        return next;
 
       // jump to next terminator
       while (*next) ++next;
diff --git a/src/ArduinoJson/Strings/ArduinoStringAdapter.hpp b/src/ArduinoJson/Strings/ArduinoStringAdapter.hpp
index 24646ccd..3797d686 100644
--- a/src/ArduinoJson/Strings/ArduinoStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/ArduinoStringAdapter.hpp
@@ -39,10 +39,6 @@ class ArduinoStringAdapter {
     return _str->length();
   }
 
-  const char* begin() const {
-    return _str->c_str();
-  }
-
   typedef storage_policies::store_by_copy storage_policy;
 
  private:
diff --git a/src/ArduinoJson/Strings/ConstRamStringAdapter.hpp b/src/ArduinoJson/Strings/ConstRamStringAdapter.hpp
index ec7d53a6..92298acf 100644
--- a/src/ArduinoJson/Strings/ConstRamStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/ConstRamStringAdapter.hpp
@@ -39,10 +39,6 @@ class ConstRamStringAdapter {
     return _str;
   }
 
-  const char* begin() const {
-    return _str;
-  }
-
   typedef storage_policies::store_by_address storage_policy;
 
  protected:
diff --git a/src/ArduinoJson/Strings/FlashStringAdapter.hpp b/src/ArduinoJson/Strings/FlashStringAdapter.hpp
index 292e348b..918a535c 100644
--- a/src/ArduinoJson/Strings/FlashStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/FlashStringAdapter.hpp
@@ -5,7 +5,6 @@
 #pragma once
 
 #include <ArduinoJson/Polyfills/pgmspace.hpp>
-#include <ArduinoJson/Strings/FlashStringIterator.hpp>
 #include <ArduinoJson/Strings/IsString.hpp>
 #include <ArduinoJson/Strings/StoragePolicy.hpp>
 
@@ -43,10 +42,6 @@ class FlashStringAdapter {
     return strlen_P(reinterpret_cast<const char*>(_str));
   }
 
-  FlashStringIterator begin() const {
-    return FlashStringIterator(_str);
-  }
-
   typedef storage_policies::store_by_copy storage_policy;
 
  private:
diff --git a/src/ArduinoJson/Strings/FlashStringIterator.hpp b/src/ArduinoJson/Strings/FlashStringIterator.hpp
deleted file mode 100644
index 9a97f324..00000000
--- a/src/ArduinoJson/Strings/FlashStringIterator.hpp
+++ /dev/null
@@ -1,44 +0,0 @@
-// ArduinoJson - https://arduinojson.org
-// Copyright Benoit Blanchon 2014-2021
-// MIT License
-
-#pragma once
-
-namespace ARDUINOJSON_NAMESPACE {
-
-class FlashStringIterator {
- public:
-  explicit FlashStringIterator(const __FlashStringHelper* ptr)
-      : _ptr(reinterpret_cast<const char*>(ptr)) {}
-
-  explicit FlashStringIterator(const char* ptr) : _ptr(ptr) {}
-
-  FlashStringIterator operator+(ptrdiff_t d) const {
-    return FlashStringIterator(_ptr + d);
-  }
-
-  ptrdiff_t operator-(FlashStringIterator other) const {
-    return _ptr - other._ptr;
-  }
-
-  FlashStringIterator operator++(int) {
-    return FlashStringIterator(_ptr++);
-  }
-
-  FlashStringIterator operator++() {
-    return FlashStringIterator(++_ptr);
-  }
-
-  bool operator!=(FlashStringIterator other) const {
-    return _ptr != other._ptr;
-  }
-
-  char operator*() const {
-    return char(pgm_read_byte(_ptr));
-  }
-
- private:
-  const char* _ptr;
-};
-
-}  // namespace ARDUINOJSON_NAMESPACE
diff --git a/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp b/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
index b9cc0bff..1055f666 100644
--- a/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/SizedFlashStringAdapter.hpp
@@ -5,7 +5,6 @@
 #pragma once
 
 #include <ArduinoJson/Namespace.hpp>
-#include <ArduinoJson/Strings/FlashStringIterator.hpp>
 #include <ArduinoJson/Strings/IsString.hpp>
 #include <ArduinoJson/Strings/StoragePolicy.hpp>
 
@@ -42,10 +41,6 @@ class SizedFlashStringAdapter {
     return _size;
   }
 
-  FlashStringIterator begin() const {
-    return FlashStringIterator(_str);
-  }
-
   typedef storage_policies::store_by_copy storage_policy;
 
  private:
diff --git a/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp b/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
index fe23408f..62460a19 100644
--- a/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/SizedRamStringAdapter.hpp
@@ -36,10 +36,6 @@ class SizedRamStringAdapter {
     return _size;
   }
 
-  const char* begin() const {
-    return _str;
-  }
-
   typedef storage_policies::store_by_copy storage_policy;
 
  private:
diff --git a/src/ArduinoJson/Strings/StdStringAdapter.hpp b/src/ArduinoJson/Strings/StdStringAdapter.hpp
index ebf4c396..3979070e 100644
--- a/src/ArduinoJson/Strings/StdStringAdapter.hpp
+++ b/src/ArduinoJson/Strings/StdStringAdapter.hpp
@@ -41,10 +41,6 @@ class StdStringAdapter {
     return _str->size();
   }
 
-  const char* begin() const {
-    return _str->c_str();
-  }
-
   typedef storage_policies::store_by_copy storage_policy;
 
  private: