diff --git a/os/utils.c b/os/utils.c
index 5162ff11a..659be30e0 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1664,6 +1664,9 @@ OsBlockSignals (void)
 #endif
 #ifdef SIGTTOU
 	sigaddset (&set, SIGTTOU);
+#endif
+#ifdef SIGCHLD
+	sigaddset (&set, SIGCHLD);
 #endif
 	sigprocmask (SIG_BLOCK, &set, &PreviousSignalMask);
     }