diff --git a/code/AssetLib/FBX/FBXImporter.cpp b/code/AssetLib/FBX/FBXImporter.cpp
index 8c908be40..f80b65cd4 100644
--- a/code/AssetLib/FBX/FBXImporter.cpp
+++ b/code/AssetLib/FBX/FBXImporter.cpp
@@ -141,7 +141,10 @@ void FBXImporter::SetupProperties(const Importer *pImp) {
 // ------------------------------------------------------------------------------------------------
 // Imports the given file into the given scene structure.
 void FBXImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler) {
-	std::unique_ptr<IOStream> stream(pIOHandler->Open(pFile, "rb"));
+	auto streamCloser = [&](IOStream *pStream) {
+		pIOHandler->Close(pStream);
+	};
+	std::unique_ptr<IOStream, decltype(streamCloser)> stream(pIOHandler->Open(pFile, "rb"), streamCloser);
 	if (!stream) {
 		ThrowException("Could not open file for reading");
 	}
diff --git a/code/AssetLib/Obj/ObjFileImporter.cpp b/code/AssetLib/Obj/ObjFileImporter.cpp
index b6e1f9061..4fa122c45 100644
--- a/code/AssetLib/Obj/ObjFileImporter.cpp
+++ b/code/AssetLib/Obj/ObjFileImporter.cpp
@@ -107,7 +107,10 @@ const aiImporterDesc *ObjFileImporter::GetInfo() const {
 void ObjFileImporter::InternReadFile(const std::string &file, aiScene *pScene, IOSystem *pIOHandler) {
     // Read file into memory
     static const std::string mode = "rb";
-    std::unique_ptr<IOStream> fileStream(pIOHandler->Open(file, mode));
+    auto streamCloser = [&](IOStream *pStream) {
+        pIOHandler->Close(pStream);
+    };
+    std::unique_ptr<IOStream, decltype(streamCloser)> fileStream(pIOHandler->Open(file, mode), streamCloser);
     if (!fileStream.get()) {
         throw DeadlyImportError("Failed to open file " + file + ".");
     }