diff --git a/Foundation/JSONSerialization.swift b/Foundation/JSONSerialization.swift
index 7cd40d1128..3c7ad5b120 100644
--- a/Foundation/JSONSerialization.swift
+++ b/Foundation/JSONSerialization.swift
@@ -305,7 +305,7 @@ private struct JSONWriter {
         let formatter: CFNumberFormatter
         formatter = CFNumberFormatterCreate(nil, CFLocaleCopyCurrent(), kCFNumberFormatterNoStyle)
         CFNumberFormatterSetProperty(formatter, kCFNumberFormatterMaxFractionDigits, NSNumber(value: 15))
-        CFNumberFormatterSetFormat(formatter, "0.###############"._cfObject)
+        CFNumberFormatterSetFormat(formatter, "0.0##############"._cfObject)
         return formatter
     }()
 
@@ -842,11 +842,6 @@ private struct JSONReader {
                     return nil
                 }
 
-                if doubleResult == doubleResult.rounded() {
-                    return (shouldUseReferenceType ? NSNumber(value: Int(doubleResult)) : Int(doubleResult),
-                            doubleDistance)
-                }
-
                 return (shouldUseReferenceType ? NSNumber(value: doubleResult) : doubleResult,
                         doubleDistance)
             }
diff --git a/TestFoundation/TestJSONSerialization.swift b/TestFoundation/TestJSONSerialization.swift
index 56fc53ad36..4771fceab0 100644
--- a/TestFoundation/TestJSONSerialization.swift
+++ b/TestFoundation/TestJSONSerialization.swift
@@ -1447,8 +1447,8 @@ extension TestJSONSerialization {
             let data = decimalArray.data(using: String.Encoding.utf8)
             let result = try JSONSerialization.jsonObject(with: data!, options: []) as? [Any]
             XCTAssertEqual(result?[0] as! Double, 12.1)
-            XCTAssertEqual(result?[1] as! Int, 10)
-            XCTAssertEqual(result?[2] as! Int, 0)
+            XCTAssertEqual(result?[1] as! Double, 10.0)
+            XCTAssertEqual(result?[2] as! Double, 0.0)
             XCTAssertEqual(result?[3] as! Double, 0.0001)
             XCTAssertEqual(result?[4] as! Int, 20)
             XCTAssertEqual(result?[5] as! Int, Int.max)