diff --git a/os/osdep.h b/os/osdep.h
index dfbfc4873..ff41f2482 100644
--- a/os/osdep.h
+++ b/os/osdep.h
@@ -173,6 +173,8 @@ void OsInit(void);
 void OsCleanup(Bool);
 void OsVendorFatalError(const char *f, va_list args) _X_ATTRIBUTE_PRINTF(1, 0);
 void OsVendorInit(void);
+
+_X_EXPORT /* needed by the int10 module, but should not be used by OOT drivers */
 void OsBlockSignals(void);
 
 _X_EXPORT /* needed by the int10 module, but should not be used by OOT drivers */