diff --git a/NEWS b/NEWS
index 3010c825d..9a9e9570b 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,10 @@ Any uppercase BUG_* names are modernish shell bug IDs.
 - Fixed a bug introduced on 2020-08-19: Ctrl+D would break after an
   interactive shell received SIGWINCH.
 
+- Fixed a bug introduced on 2020-05-21: on an interactive shell, command lines
+  containing a syntax error were not added to the command history file and
+  sometimes corrupted the command history.
+
 2021-03-05:
 
 - Unbalanced quotes and backticks now correctly produce a syntax error
diff --git a/src/cmd/ksh93/sh/io.c b/src/cmd/ksh93/sh/io.c
index 0f4be76b5..4b83a7e38 100644
--- a/src/cmd/ksh93/sh/io.c
+++ b/src/cmd/ksh93/sh/io.c
@@ -1712,11 +1712,6 @@ void	sh_iorestore(Shell_t *shp, int last, int jmpval)
 	register int 	origfd, savefd, fd;
 	int flag = (last&IOSUBSHELL);
 	last &= ~IOSUBSHELL;
-	/*
-	 * There was an issue with truncating files (see 'ftruncate' below) that was caused by
-	 * out-of-sync streams. So, to be safe, sync all streams before restoring file descriptors.
-	 */
-	sfsync(NULL);
 	for (fd = shp->topfd - 1; fd >= last; fd--)
 	{
 		if(!flag && filemap[fd].subshell)
@@ -1740,7 +1735,10 @@ void	sh_iorestore(Shell_t *shp, int last, int jmpval)
 			return;
 		}
 		if(filemap[fd].tname == Empty && shp->exitval==0)
+		{
+			sfsync(NIL(Sfio_t*));
 			ftruncate(origfd,lseek(origfd,0,SEEK_CUR));
+		}
 		else if(filemap[fd].tname)
 			io_usename(filemap[fd].tname,(int*)0,origfd,shp->exitval?2:1);
 		sh_close(origfd);
diff --git a/src/cmd/ksh93/tests/pty.sh b/src/cmd/ksh93/tests/pty.sh
index 733a269d5..69b30f3e3 100755
--- a/src/cmd/ksh93/tests/pty.sh
+++ b/src/cmd/ksh93/tests/pty.sh
@@ -107,7 +107,6 @@ if	! pty $bintrue < /dev/null
 then	err_exit pty command hangs on $bintrue -- tests skipped
 	exit 0
 fi
-
 # err_exit #
 tst $LINENO <<"!"
 L POSIX sh 026(C)
@@ -712,5 +711,21 @@ r ^:test-3: ls vi_completion_A_file\r\n$
 r ^vi_completion_A_file\r\n$
 !
 
+# err_exit #
+tst $LINENO <<"!"
+L syntax error added to history file
+
+# https://github.com/ksh93/ksh/issues/209
+
+d 10
+p :test-1:
+w do something
+r ^:test-1: do something\r\n$
+r : syntax error: `do' unexpected\r\n$
+w fc -lN1
+r ^:test-2: fc -lN1\r\n$
+r \tdo something\r\n$
+!
+
 # ======
 exit $((Errors<125?Errors:125))