diff --git a/NEWS b/NEWS
new file mode 100644
index 000000000..1280b3977
--- /dev/null
+++ b/NEWS
@@ -0,0 +1,25 @@
+This documents significant changes in the 93u+m branch of AT&T ksh93.
+For full details, see the git log at:
+	https://github.com/modernish/ksh
+
+Any uppercase BUG_* names are modernish shell bug IDs.
+
+2020-05-13:
+
+- Fix BUG_CASELIT: an undocumented 'case' pattern matching misbehaviour that
+  goes back to the original Bourne shell, but wasn't discovered until 2018.
+  If a pattern doesn't match as a pattern, it was tried again as a literal
+  string. This broke common validation use cases, e.g.:
+      n='[0-9]'
+      case $n in
+      ( [0-9] )  echo "$n is a number" ;;
+      esac
+  would output "[0-9] is a number" as the literal string fallback matches the
+  pattern. As this misbehaviour was never documented anywhere (not for Bourne,
+  ksh88, or ksh93), and it was never replicated in other shells (not even in
+  ksh88 clones pdksh and mksh), it is unlikely any scripts rely on it.
+     Of course, a literal string fallback, should it be needed, is trivial to
+  implement correctly without this breakage:
+      case $n in
+      ( [0-9] | "[0-9]")  echo "$n is a number or the number pattern" ;;
+      esac
diff --git a/src/cmd/ksh93/sh/xec.c b/src/cmd/ksh93/sh/xec.c
index c370477ad..9718266c0 100644
--- a/src/cmd/ksh93/sh/xec.c
+++ b/src/cmd/ksh93/sh/xec.c
@@ -65,7 +65,6 @@
 #endif /* SHOPT_SPAWN */
 
 static void	sh_funct(Shell_t *,Namval_t*, int, char*[], struct argnod*,int);
-static int	trim_eq(const char*, const char*);
 static void	coproc_init(Shell_t*, int pipes[]);
 
 static void	*timeout;
@@ -2556,8 +2555,7 @@ int sh_exec(register const Shnode_t *t, int flags)
 						s = rex->argval;
 					type = (rex->argflag&ARG_RAW);
 					if((type && strcmp(r,s)==0) ||
-						(!type && (strmatch(r,s)
-						|| trim_eq(r,s))))
+						(!type && strmatch(r,s)))
 					{
 						do	sh_exec(t->reg.regcom,(t->reg.regflag?(flags&sh_state(SH_ERREXIT)):flags));
 						while(t->reg.regflag &&
@@ -2983,24 +2981,6 @@ int sh_run(int argn, char *argv[])
 	return(argn);
 }
 
-/*
- * test for equality with second argument trimmed
- * returns 1 if r == trim(s) otherwise 0
- */
-
-static int trim_eq(register const char *r,register const char *s)
-{
-	register char c;
-	while(c = *s++)
-	{
-		if(c=='\\')
-			c = *s++;
-		if(c && c != *r++)
-			return(0);
-	}
-	return(*r==0);
-}
-
 /*
  * print out the command line if set -x is on
  */