diff --git a/storage/ndb/include/portlib/NdbThread.h b/storage/ndb/include/portlib/NdbThread.h
index 569048cf6c8..373e2218c6c 100644
--- a/storage/ndb/include/portlib/NdbThread.h
+++ b/storage/ndb/include/portlib/NdbThread.h
@@ -41,7 +41,7 @@ struct NdbThread;
   signum set in g_ndb_shm_signum in a portable manner.
 */
 #ifdef NDB_SHM_TRANSPORTER
-void NdbThread_set_shm_sigmask(bool block);
+void NdbThread_set_shm_sigmask(my_bool block);
 #endif
 
 /**