diff --git a/NEWS b/NEWS
index d55fd75fa..fe6b22f7e 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,11 @@ For full details, see the git log at: https://github.com/ksh93/ksh
 
 Any uppercase BUG_* names are modernish shell bug IDs.
 
+2020-07-06:
+
+- 'notty' is now written to the ksh auditing file instead of '(null)' if
+  the user's tty could not be determined.
+
 2020-07-05:
 
 - In UTF-8 locales, fix corruption of the shell's internal string quoting
diff --git a/src/cmd/ksh93/edit/history.c b/src/cmd/ksh93/edit/history.c
index d6737e209..f40f27b4a 100644
--- a/src/cmd/ksh93/edit/history.c
+++ b/src/cmd/ksh93/edit/history.c
@@ -395,7 +395,7 @@ retry:
 			if(fd>=0)
 			{
 				fcntl(fd,F_SETFD,FD_CLOEXEC);
-				hp->tty = strdup(ttyname(2));
+				hp->tty = strdup(isatty(2)?ttyname(2):"notty");
 				hp->auditfp = sfnew((Sfio_t*)0,NULL,-1,fd,SF_WRITE);
 			}
 		}
diff --git a/src/cmd/ksh93/include/version.h b/src/cmd/ksh93/include/version.h
index 2ee19b9b1..575941029 100644
--- a/src/cmd/ksh93/include/version.h
+++ b/src/cmd/ksh93/include/version.h
@@ -17,4 +17,4 @@
 *                  David Korn <dgk@research.att.com>                   *
 *                                                                      *
 ***********************************************************************/
-#define SH_RELEASE	"93u+m 2020-07-05"
+#define SH_RELEASE	"93u+m 2020-07-06"