diff --git a/src/ArduinoJson/Numbers/FloatTraits.hpp b/src/ArduinoJson/Numbers/FloatTraits.hpp
index 1c4559d8..5a932f79 100644
--- a/src/ArduinoJson/Numbers/FloatTraits.hpp
+++ b/src/ArduinoJson/Numbers/FloatTraits.hpp
@@ -117,15 +117,6 @@ struct FloatTraits<T, 8 /*64bits*/> {
     return forge(0x7FEFFFFF, 0xFFFFFFFF);
   }
 
-  template <typename TOut>
-  static
-      typename enable_if<is_integral<TOut>::value && sizeof(TOut) < sizeof(T),
-                         T>::type
-      highest_for() {
-    // This conversion is safe because the destination type is smaller
-    return highest();
-  }
-
   template <typename TOut>
   static typename enable_if<is_integral<TOut>::value &&
                                 is_signed<TOut>::value && sizeof(TOut) == 8,
@@ -238,15 +229,6 @@ struct FloatTraits<T, 4 /*32bits*/> {
     return forge(0x7f7fffff);
   }
 
-  template <typename TOut>
-  static
-      typename enable_if<is_integral<TOut>::value && sizeof(TOut) < sizeof(T),
-                         T>::type
-      highest_for() {
-    // This conversion is safe because the destination type is smaller
-    return highest();
-  }
-
   template <typename TOut>
   static typename enable_if<is_integral<TOut>::value &&
                                 is_signed<TOut>::value && sizeof(TOut) == 4,
diff --git a/src/ArduinoJson/Numbers/convertNumber.hpp b/src/ArduinoJson/Numbers/convertNumber.hpp
index 9bf54e8d..a9072a5c 100644
--- a/src/ArduinoJson/Numbers/convertNumber.hpp
+++ b/src/ArduinoJson/Numbers/convertNumber.hpp
@@ -96,21 +96,32 @@ canConvertNumber(TIn value) {
   return value <= TIn(numeric_limits<TOut>::highest());
 }
 
-// float32 -> int16
-// float32 -> int32
-// float32 -> int64
 // float32 -> int8
-// float32 -> uint32
-// float32 -> uint64
+// float32 -> int16
 // float64 -> int32
-// float64 -> int64
-// float64 -> uint64
 template <typename TOut, typename TIn>
-typename enable_if<is_floating_point<TIn>::value && is_integral<TOut>::value,
+typename enable_if<is_floating_point<TIn>::value && is_integral<TOut>::value &&
+                       sizeof(TOut) < sizeof(TIn),
                    bool>::type
 canConvertNumber(TIn value) {
   return value >= numeric_limits<TOut>::lowest() &&
-         value <= numeric_limits<TOut>::highest() &&
+         value <= numeric_limits<TOut>::highest();
+}
+
+// float32 -> int32
+// float32 -> uint32
+// float32 -> int64
+// float32 -> uint64
+// float64 -> int64
+// float64 -> uint64
+template <typename TOut, typename TIn>
+typename enable_if<is_floating_point<TIn>::value && is_integral<TOut>::value &&
+                       sizeof(TOut) >= sizeof(TIn),
+                   bool>::type
+canConvertNumber(TIn value) {
+  // Avoid error "9.22337e+18 is outside the range of representable values of
+  // type 'long'"
+  return value >= numeric_limits<TOut>::lowest() &&
          value <= FloatTraits<TIn>::template highest_for<TOut>();
 }