diff --git a/windows/Package.swift b/windows/Package.swift
index bdd9a7b..083c8ed 100644
--- a/windows/Package.swift
+++ b/windows/Package.swift
@@ -32,12 +32,14 @@ let package = Package(
         ),
         // A C library containing additional Windows SDK functions that arent included in the default WinSDK module
         .target(
-            name: "WinSDKExtras"
+            name: "WinSDKExtras",
+            swiftSettings: [.interoperabilityMode(.Cxx)]
         ),
         // A collection of utility functions for the Windows platform
         .target(
             name: "WindowsUtils",
             dependencies: [ .target(name: "WinSDKExtras") ],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
         // Code shared between the sandbox and the runtime
@@ -48,18 +50,21 @@ let package = Package(
         .executableTarget(
             name: "SandboxTest",
             dependencies: [ .target(name: "WindowsUtils") ],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
         // The generic sandbox library
         .target(
             name: "Sandbox",
             dependencies: [ .target(name: "WinSDKExtras"), .target(name: "WindowsUtils"), .target(name: "Shared")],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
         // The Minecraft/Fabric specific parts of the sandbox
         .target(
             name: "FabricSandbox",
             dependencies: [ .target(name: "Jni"), .target(name: "WinSDKExtras"), .target(name: "WindowsUtils"), .target(name: "Sandbox"), .product(name: "Logging", package: "swift-log")],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
         // The swift code that is used in the sandboxed process, invoked via the hook
@@ -79,11 +84,13 @@ let package = Package(
         .executableTarget(
             name: "Packager",
             dependencies: [.target(name: "WinSDKExtras"), .target(name: "WindowsUtils"), .target(name: "Sandbox"), .product(name: "Logging", package: "swift-log")],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
         .testTarget(
             name: "FabricSandboxTests",
             dependencies: [ .target(name: "FabricSandbox"), .target(name: "WindowsUtils"), .product(name: "Testing", package: "swift-testing")],
+            swiftSettings: [.interoperabilityMode(.Cxx)],
             linkerSettings: linkerSettings
         ),
     ],
diff --git a/windows/Sources/FabricSandbox/JniEntrypoint.swift b/windows/Sources/FabricSandbox/JniEntrypoint.swift
index 6daf48f..01ce8d2 100644
--- a/windows/Sources/FabricSandbox/JniEntrypoint.swift
+++ b/windows/Sources/FabricSandbox/JniEntrypoint.swift
@@ -2,12 +2,12 @@ import Jni
 import WinSDK
 
 @_cdecl("Java_net_fabricmc_sandbox_Main_nativeEntrypoint")
-public func entrypoint(env: UnsafeMutablePointer<JNIEnv?>!, clazz: jclass!) {
+public func entrypoint(env: UnsafeMutablePointer<JNIEnv>, clazz: jclass!) {
   do {
     try FabricSandbox().run()
   } catch {
-    let jni = env.pointee!.pointee
-    let runtimeException = jni.FindClass(env, "java/lang/RuntimeException")!
-    let _ = jni.ThrowNew(env, runtimeException, "\(error)")
+    var jni = env.pointee
+    let runtimeException = jni.FindClass("java/lang/RuntimeException")!
+    let _ = jni.ThrowNew(runtimeException, "\(error)")
   }
 }
diff --git a/windows/Sources/FabricSandbox/String+Jni.swift b/windows/Sources/FabricSandbox/String+Jni.swift
index 9abda5b..e3553ea 100644
--- a/windows/Sources/FabricSandbox/String+Jni.swift
+++ b/windows/Sources/FabricSandbox/String+Jni.swift
@@ -2,10 +2,10 @@ import Jni
 
 extension String {
   // Construct a String from a jstring
-  init(_ env: UnsafeMutablePointer<JNIEnv?>!, jstring: jstring!) {
-    let jni = env.pointee!.pointee
-    let chars = jni.GetStringChars(env, jstring, nil)!
-    defer { jni.ReleaseStringChars(env, jstring, chars) }
+  init(_ env: UnsafeMutablePointer<JNIEnv>, jstring: jstring!) {
+    var jni = env.pointee
+    let chars = jni.GetStringChars(jstring, nil)!
+    defer { jni.ReleaseStringChars(jstring, chars) }
     self = String(decodingCString: chars, as: UTF16.self)
   }
 }
diff --git a/windows/Sources/WinSDKExtras/WinSdkExtras.c b/windows/Sources/WinSDKExtras/WinSDKExtras.cpp
similarity index 97%
rename from windows/Sources/WinSDKExtras/WinSdkExtras.c
rename to windows/Sources/WinSDKExtras/WinSDKExtras.cpp
index 181b356..dc9c683 100644
--- a/windows/Sources/WinSDKExtras/WinSdkExtras.c
+++ b/windows/Sources/WinSDKExtras/WinSDKExtras.cpp
@@ -1,4 +1,4 @@
-#include "WinSdkExtras.h"
+#include "WinSDKExtras.h"
 
 #include <userenv.h>
 #include <VersionHelpers.h>
@@ -65,7 +65,7 @@ DWORD _SECURITY_MAX_SID_SIZE() {
 }
 
 LPWCH _CASTSID(PSID pSid) {
-    return (LPWCH)pSid;
+    return static_cast<LPWCH>(pSid);
 }
 
 LPPROC_THREAD_ATTRIBUTE_LIST allocateAttributeList(size_t size) {
diff --git a/windows/Sources/WinSDKExtras/include/module.modulemap b/windows/Sources/WinSDKExtras/include/module.modulemap
new file mode 100644
index 0000000..d94ce19
--- /dev/null
+++ b/windows/Sources/WinSDKExtras/include/module.modulemap
@@ -0,0 +1,4 @@
+module WinSDKExtras {
+    header "WinSDKExtras.h"
+    export *
+}
\ No newline at end of file