diff --git a/src/security/sec-tpm-file.hpp b/src/security/sec-tpm-file.hpp
index 0f1d8be..d9f95c4 100644
--- a/src/security/sec-tpm-file.hpp
+++ b/src/security/sec-tpm-file.hpp
@@ -60,7 +60,7 @@
   }
 
   virtual bool
-  getInTerminal()
+  getInTerminal() const
   {
     return m_inTerminal;
   }