diff --git a/src/include/final/fsystemimpl.h b/src/include/final/fsystemimpl.h
index c3e2800b..4c30b7df 100644
--- a/src/include/final/fsystemimpl.h
+++ b/src/include/final/fsystemimpl.h
@@ -77,7 +77,11 @@ class FSystemImpl : public FSystem
 #if defined(__linux__)
 #if defined(__x86_64__) || defined(__i386) || defined(__arm__)
       return ::inb (port);
+#else
+      return 0;
 #endif
+#else
+      return 0;
 #endif
     }