diff --git a/os/osdep.h b/os/osdep.h
index 5a8117d78..dfbfc4873 100644
--- a/os/osdep.h
+++ b/os/osdep.h
@@ -174,7 +174,10 @@ void OsCleanup(Bool);
 void OsVendorFatalError(const char *f, va_list args) _X_ATTRIBUTE_PRINTF(1, 0);
 void OsVendorInit(void);
 void OsBlockSignals(void);
+
+_X_EXPORT /* needed by the int10 module, but should not be used by OOT drivers */
 void OsReleaseSignals(void);
+
 void OsResetSignals(void);
 void OsAbort(void) _X_NORETURN;
 void AbortServer(void) _X_NORETURN;