diff -ur mksh.orig/check.t mksh/check.t
--- mksh.orig/check.t	2020-10-31 04:53:30.000000000 +0100
+++ mksh/check.t	2021-01-18 19:12:47.413180226 +0100
@@ -2484,7 +2484,7 @@
 	!bc +bc ,bc 0bc 1bc ^bc cbc
 	!bc +bc ,bc -bc 0bc 1bc ^bc cbc
 	abc bbc
-	^bc abc bbc
+	!bc +bc ,bc -bc 0bc 1bc ^bc cbc
 	+bc ,bc -bc
 	-bc 0bc 1bc
 ---
diff -ur mksh.orig/eval.c mksh/eval.c
--- mksh.orig/eval.c	2020-05-05 23:34:54.000000000 +0200
+++ mksh/eval.c	2021-01-18 19:12:47.411180226 +0100
@@ -1108,6 +1108,7 @@
 				switch (ord(c)) {
 				case ORD('['):
 				case ORD('!'):
+				case ORD(NOT2):
 				case ORD('-'):
 				case ORD(']'):
 					/*
diff -ur mksh.orig/misc.c mksh/misc.c
--- mksh.orig/misc.c	2020-08-27 21:53:12.000000000 +0200
+++ mksh/misc.c	2021-01-18 19:12:47.411180226 +0100
@@ -1018,7 +1018,7 @@
 	char *subp;
 
 	/* check for negation */
-	if (ISMAGIC(p[0]) && ord(p[1]) == ORD('!')) {
+	if (ISMAGIC(p[0]) && (ord(p[1]) == ORD('!') || ord(p[1]) == ORD(NOT2))) {
 		p += 2;
 		negated = true;
 	}
diff -ur mksh.orig/sh.h mksh/sh.h
--- mksh.orig/sh.h	2020-10-31 04:53:33.000000000 +0100
+++ mksh/sh.h	2021-01-18 19:12:47.412180226 +0100
@@ -580,6 +580,7 @@
  */
 #define MAGIC		KSH_BEL	/* prefix for *?[!{,} during expand */
 #define ISMAGIC(c)	(ord(c) == ORD(MAGIC))
+#define NOT2		'^'
 
 EXTERN const char *safe_prompt; /* safe prompt if PS1 substitution fails */
 
Only in mksh: sh.h.orig