diff --git a/Sources/SmithyJSON/Reader/Reader.swift b/Sources/SmithyJSON/Reader/Reader.swift
index f70752696..9836bd14b 100644
--- a/Sources/SmithyJSON/Reader/Reader.swift
+++ b/Sources/SmithyJSON/Reader/Reader.swift
@@ -16,6 +16,7 @@ import struct Foundation.Data
 import struct Foundation.Date
 import class Foundation.NSNull
 import class Foundation.NSNumber
+import class Foundation.NSDecimalNumber
 import func CoreFoundation.CFGetTypeID
 import func CoreFoundation.CFBooleanGetTypeID
 
@@ -126,7 +127,12 @@ public extension Reader {
 
     func readIfPresent() throws -> Double? {
         switch jsonNode {
-        case .number(let number): return number.doubleValue
+        case .number(let number):
+            if let decimalNumber = number as? NSDecimalNumber {
+                return Double("\(decimalNumber.decimalValue)")
+            } else {
+                return number.doubleValue
+            }
         case .string(let string):
             switch string {
             case "NaN": return .nan
diff --git a/Tests/SmithyJSONTests/FloatingPointTests.swift b/Tests/SmithyJSONTests/FloatingPointTests.swift
new file mode 100644
index 000000000..693cd3830
--- /dev/null
+++ b/Tests/SmithyJSONTests/FloatingPointTests.swift
@@ -0,0 +1,46 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import XCTest
+@_spi(SmithyReadWrite) import SmithyReadWrite
+@_spi(SmithyReadWrite) import SmithyJSON
+
+// It appears that the doubleValue property on NSNumber & its associated types can sometimes lose
+// precision from the original number.
+//
+// This set of tests is intended to verify that Doubles and Floats can be read accurately from JSON.
+
+final class FloatingPointTests: XCTestCase {
+
+    static var originalFloats = [Float]()
+    static var floatData = Data()
+    static var originalDoubles = [Double]()
+    static var doubleData = Data()
+
+    // Renders 250 floats & doubles to JSON arrays.  Numbers are random so they will
+    // likely use all available decimal places.
+    static override func setUp() {
+        originalFloats = (1..<250).map { _ in Float.random(in: 0.0...1.0) }
+        originalDoubles = (1..<250).map { _ in Double.random(in: 0.0...1.0) }
+        floatData = try! JSONEncoder().encode(originalFloats)
+        doubleData = try! JSONEncoder().encode(originalDoubles)
+    }
+
+    // Read the floats from JSON using JSONReader, and compare the values to the original.
+    func test_floatRead() throws {
+        let reader = try Reader.from(data: Self.floatData)
+        let floats = try reader.readList(memberReadingClosure: ReadingClosures.readFloat(from:), memberNodeInfo: "", isFlattened: false)
+        XCTAssert(floats == Self.originalFloats)
+    }
+
+    // Read the doubles from JSON using JSONReader, and compare the values to the original.
+    func test_doubleRead() throws {
+        let reader = try Reader.from(data: Self.doubleData)
+        let doubles = try reader.readList(memberReadingClosure: ReadingClosures.readDouble(from:), memberNodeInfo: "", isFlattened: false)
+        XCTAssert(doubles == Self.originalDoubles)
+    }
+}