diff --git a/Libraries/LibCore/CIODevice.h b/Libraries/LibCore/CIODevice.h
index b50e8135b8..e57c650899 100644
--- a/Libraries/LibCore/CIODevice.h
+++ b/Libraries/LibCore/CIODevice.h
@@ -21,6 +21,7 @@ public:
 
     int fd() const { return m_fd; }
     unsigned mode() const { return m_mode; }
+    bool is_open() const { return m_mode != NotOpen; }
     bool eof() const { return m_eof; }
 
     int error() const { return m_error; }