diff --git a/file.cpp b/file.cpp
index c8a2861..b018b15 100644
--- a/file.cpp
+++ b/file.cpp
@@ -23,6 +23,8 @@
 struct File_impl {
 	bool _ioErr;
 	File_impl() : _ioErr(false) {}
+	virtual ~File_impl() {}
+
 	virtual bool open(const char *path, const char *mode) = 0;
 	virtual void close() = 0;
 	virtual void seek(int32_t off) = 0;