diff --git a/src/conio/cterm.c b/src/conio/cterm.c
index 46cbd7329c30e4ef105faf7a5fcec349d4a648cb..1d58c53afca590b9cf5d91feaa5448879b5e518e 100644
--- a/src/conio/cterm.c
+++ b/src/conio/cterm.c
@@ -2815,7 +2815,7 @@ int CIOLIBCALL cterm_openlog(struct cterminal *cterm, char *logfile, int logtype
 	if(!cterm->started)
 		cterm_start(cterm);
 
-	cterm->logfile=fopen(logfile, "a");
+	cterm->logfile=fopen(logfile, "ab");
 	if(cterm->logfile==NULL)
 		return(0);
 	cterm->log=logtype;