diff --git a/aegisub/libaegisub/common/fs.cpp b/aegisub/libaegisub/common/fs.cpp
index 26c1a99c4..599046778 100644
--- a/aegisub/libaegisub/common/fs.cpp
+++ b/aegisub/libaegisub/common/fs.cpp
@@ -23,7 +23,9 @@
 #include "libaegisub/log.h"
 
 #include <boost/algorithm/string/predicate.hpp>
+#define BOOST_NO_SCOPED_ENUMS
 #include <boost/filesystem.hpp>
+#undef BOOST_NO_SCOPED_ENUMS
 
 namespace bfs = boost::filesystem;
 namespace ec = boost::system::errc;
@@ -94,11 +96,6 @@ namespace agi { namespace fs {
 		CHECKED_CALL(bfs::rename(from, to, ec), from, to);
 	}
 
-	void Copy(path const& from, path const& to) {
-		CreateDirectory(to.parent_path());
-		CHECKED_CALL(bfs::copy_file(from, to, bfs::copy_option::overwrite_if_exists, ec), from, to);
-	}
-
 	bool HasExtension(path const& p, std::string const& ext) {
 		auto filename = p.filename().string();
 		if (filename.size() < ext.size() + 1) return false;
diff --git a/aegisub/libaegisub/lagi_pre.h b/aegisub/libaegisub/lagi_pre.h
index 16776817b..044eedac1 100644
--- a/aegisub/libaegisub/lagi_pre.h
+++ b/aegisub/libaegisub/lagi_pre.h
@@ -61,6 +61,9 @@
 // Boost
 #include <boost/container/list.hpp>
 #include <boost/container/map.hpp>
+#define BOOST_NO_SCOPED_ENUMS
+#include <boost/filesystem.hpp>
+#undef BOOST_NO_SCOPED_ENUMS
 
 #ifdef __DEPRECATED // Dodge GCC warnings
 # undef __DEPRECATED
diff --git a/aegisub/libaegisub/unix/fs.cpp b/aegisub/libaegisub/unix/fs.cpp
index 63c22450e..6c59766a2 100644
--- a/aegisub/libaegisub/unix/fs.cpp
+++ b/aegisub/libaegisub/unix/fs.cpp
@@ -16,7 +16,9 @@
 
 #include "config.h"
 
+#include "libaegisub/access.h"
 #include "libaegisub/fs.h"
+#include "libaegisub/io.h"
 
 #include <boost/filesystem.hpp>
 #include <fcntl.h>
@@ -40,6 +42,15 @@ void Touch(path const& file) {
 	}
 }
 
+void Copy(fs::path const& from, fs::path const& to) {
+	acs::CheckFileRead(from);
+	CreateDirectory(to.parent_path());
+	acs::CheckDirWrite(to.parent_path());
+
+	std::unique_ptr<std::istream> in(io::Open(from, true));
+	io::Save(to).Get() << in->rdbuf();
+}
+
 struct DirectoryIterator::PrivData {
 	boost::system::error_code ec;
 	bfs::directory_iterator it;
diff --git a/aegisub/libaegisub/windows/fs.cpp b/aegisub/libaegisub/windows/fs.cpp
index 57c29d10f..b0a8d5cdd 100644
--- a/aegisub/libaegisub/windows/fs.cpp
+++ b/aegisub/libaegisub/windows/fs.cpp
@@ -72,6 +72,23 @@ void Touch(path const& file) {
 		throw EnvironmentError("SetFileTime failed with error: " + util::ErrorString(GetLastError()));
 }
 
+void Copy(fs::path const& from, fs::path const& to) {
+	acs::CheckFileRead(from);
+	CreateDirectory(to.parent_path());
+	acs::CheckDirWrite(to.parent_path());
+
+	if (!CopyFile(from.wstring().c_str(), to.wstring().c_str(), false)) {
+		switch (GetLastError()) {
+		case ERROR_FILE_NOT_FOUND:
+			throw FileNotFound(from);
+		case ERROR_ACCESS_DENIED:
+			throw fs::WriteDenied("Could not overwrite " + to.string());
+		default:
+			throw fs::WriteDenied("Could not copy: " + util::ErrorString(GetLastError()));
+		}
+	}
+}
+
 struct DirectoryIterator::PrivData {
 	scoped_holder<HANDLE, BOOL (__stdcall *)(HANDLE)> h;
 	PrivData() : h(INVALID_HANDLE_VALUE, FindClose) { }