diff --git a/src/cmd/ksh93/sh/nvdisc.c b/src/cmd/ksh93/sh/nvdisc.c
index 0e5b53b0e..38717b834 100644
--- a/src/cmd/ksh93/sh/nvdisc.c
+++ b/src/cmd/ksh93/sh/nvdisc.c
@@ -367,7 +367,7 @@ static void	assign(Namval_t *np,const char* val,int flags,Namfun_t *handle)
 done:
 	if(bp== &block)
 		block_done(bp);
-	if(nq && nq->nvalue.rp->running==1)
+	if(nq && nq->nvalue.rp && nq->nvalue.rp->running==1)
 	{
 		nq->nvalue.rp->running=0;
 		_nv_unset(nq,0);
diff --git a/src/cmd/ksh93/tests/variables.sh b/src/cmd/ksh93/tests/variables.sh
index 0e496a2c3..5c48b2113 100755
--- a/src/cmd/ksh93/tests/variables.sh
+++ b/src/cmd/ksh93/tests/variables.sh
@@ -1369,5 +1369,13 @@ got=$("$SHELL" -c $'foo=baz; foo+=_foo "$SHELL" -c \'print $foo\'; print $foo')
 [[ $exp == "$got" ]] || err_exit "using the += operator for invocation-local assignments changes variables outside of the invocation-local scope" \
 	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
 
+# ======
+# Crash when setting attribute after getn (numeric get) discipline
+# https://github.com/ksh93/ksh/issues/435#issuecomment-1148813866
+got=$("$SHELL" -c 'foo.getn() { .sh.value=2.3*4.5; }; typeset -F2 foo; typeset -p foo' 2>&1)
+exp='typeset -F 2 foo=10.35'
+[[ $got == "$exp" ]] || err_exit "Setting attribute after setting getn discipline fails" \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+
 # ======
 exit $((Errors<125?Errors:125))