diff --git a/Tests/CryptoTests/Encodings/DERTests.swift b/Tests/CryptoTests/Encodings/DERTests.swift
index 2b2dafee3..7b1db97ae 100644
--- a/Tests/CryptoTests/Encodings/DERTests.swift
+++ b/Tests/CryptoTests/Encodings/DERTests.swift
@@ -49,7 +49,7 @@ class DERTests: XCTestCase {
     }
 
     func randomBytes(count: Int) -> [UInt8] {
-        #if (os(macOS) || os(iOS) || os(watchOS) || os(tvOS)) || os(Linux) || os(Android)
+        #if (os(macOS) || os(iOS) || os(watchOS) || os(tvOS)) || os(Linux) || os(Android) || os(Windows)
         var rng = SystemRandomNumberGenerator()
         return (0..<count).map { _ in rng.next() }
         #else