diff --git a/src/backend.c b/src/backend.c
index d1bc46d..e511910 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1540,6 +1540,7 @@ f_debug_message (svalue_t *sp)
 	      || (sp->u.number & DMSG_LOGFILE))
 		fputs(pTxt, stdout);
 #endif
+            fflush(stdout);
 
             slen -= strlen(pTxt);
             pTxt += strlen(pTxt);