diff --git a/NEWS b/NEWS
index b90627569873..c3f218a76696 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,9 @@ Uppercase BUG_* IDs are shell bug IDs as used by the Modernish shell library.
 
 2024-08-26:
 
+- Fixed an infinite loop that occurred when a syntax error was thrown
+  for an arithmetic 'for' loop on the interactive command line.
+
 - [v1.1] Backported a change to '_' in types from the unreleased ksh 93v-
   beta. If a 'typeset -T' type declaration sets a discipline function for
   one of its subvariables (such as var.get() or var.getn()), then, within
diff --git a/src/cmd/ksh93/include/shlex.h b/src/cmd/ksh93/include/shlex.h
index 2a46d0de1f9f..3aa1d403bb44 100644
--- a/src/cmd/ksh93/include/shlex.h
+++ b/src/cmd/ksh93/include/shlex.h
@@ -52,7 +52,7 @@ struct _shlex_pvt_lexdata_
 	char		docword;
 	char		nested_tilde;
 	char 		*docend;
-	char		noarg;
+	char		inlexskip;	/* set when sh_lex() is called from sh_lexskip() */
 	char		warn;
 	char		message;
 	char		arith;
diff --git a/src/cmd/ksh93/sh/lex.c b/src/cmd/ksh93/sh/lex.c
index ed8ed2db606e..d72f7feb98a4 100644
--- a/src/cmd/ksh93/sh/lex.c
+++ b/src/cmd/ksh93/sh/lex.c
@@ -150,13 +150,13 @@ static void lex_advance(Sfio_t *iop, const char *buff, int size, void *context)
 	{
 		size -= (lp->lexd.first-(char*)buff);
 		buff = lp->lexd.first;
-		if(!lp->lexd.noarg)
+		if(!lp->lexd.inlexskip)
 			lp->arg = stkseek(sh.stk,ARGVAL);
 #if SHOPT_KIA
 		lp->lexd.kiaoff += ARGVAL;
 #endif /* SHOPT_KIA */
 	}
-	if(size>0 && (lp->arg||lp->lexd.noarg))
+	if(size>0 && (lp->arg||lp->lexd.inlexskip))
 	{
 		sfwrite(sh.stk,buff,size);
 		lp->lexd.first = 0;
@@ -344,7 +344,7 @@ int sh_lex(Lex_t* lp)
 				/* end-of-file */
 				if(mode==ST_BEGIN)
 					return lp->token=EOFSYM;
-				if(mode >ST_NORM && lp->lexd.level>0)
+				if(mode >ST_NORM && lp->lexd.level>0 && !lp->lexd.inlexskip)
 				{
 					switch(c=endchar(lp))
 					{
@@ -706,7 +706,7 @@ int sh_lex(Lex_t* lp)
 				mode = ST_NORM;
 				continue;
 			case S_LIT:
-				if(oldmode(lp)==ST_NONE && !lp->lexd.noarg)	/* in ((...)) */
+				if(oldmode(lp)==ST_NONE && !lp->lexd.inlexskip)	/* in ((...)) */
 				{
 					if((c=fcpeek(0))==LPAREN || c==RPAREN || c=='$' || c==LBRACE || c==RBRACE || c=='[' || c==']')
 					{
@@ -1741,13 +1741,13 @@ void sh_lexskip(Lex_t *lp,int close, int copy, int  state)
 	char	*cp;
 	lp->lexd.nest = close;
 	lp->lexd.lex_state = state;
-	lp->lexd.noarg = 1;
+	lp->lexd.inlexskip = 1;
 	if(copy)
 		fcnotify(lex_advance,lp);
 	else
 		lp->lexd.nocopy++;
 	sh_lex(lp);
-	lp->lexd.noarg = 0;
+	lp->lexd.inlexskip = 0;
 	if(copy)
 	{
 		fcnotify(0,lp);
diff --git a/src/cmd/ksh93/tests/loop.sh b/src/cmd/ksh93/tests/loop.sh
index 8c4b2e94c42f..a3db88da2f0a 100755
--- a/src/cmd/ksh93/tests/loop.sh
+++ b/src/cmd/ksh93/tests/loop.sh
@@ -69,5 +69,17 @@ got=$(for i in a b c; do print -n $i; for j in 1 2 3; do print -n $j; for k in x
 exp=a1xb1xc1x
 [[ $got == "$exp" ]] || err_exit "'continue 3' broken (expected '$exp', got '$got')"
 
+# ======
+# arithmetic for
+
+got=$(eval 'for((i=0,i<10,i++)); do :; done' 2>&1)
+exp=': syntax error at line 1: `))'\'' unexpected'
+[[ $got == *"$exp" ]] || err_exit "arithmetic for syntax error" \
+	"(expected match of *$(printf %q "$exp"), got $(printf %q "$got"))"
+got=$(eval 'for(())' 2>&1)
+exp=': syntax error at line 1: `))'\'' unexpected'
+[[ $got == *"$exp" ]] || err_exit "arithmetic for syntax error" \
+	"(expected match of *$(printf %q "$exp"), got $(printf %q "$got"))"
+
 # ======
 exit $((Errors<125?Errors:125))