diff --git a/src/cmd/ksh93/sh/name.c b/src/cmd/ksh93/sh/name.c
index 9fb3c5776..f6aa65b1c 100644
--- a/src/cmd/ksh93/sh/name.c
+++ b/src/cmd/ksh93/sh/name.c
@@ -2501,7 +2501,11 @@ void	_nv_unset(register Namval_t *np,int flags)
 				}
 				dtclose(rp->sdict);
 			}
-			stakdelete(slp->slptr);
+			if(slp->slptr)
+			{
+				stakdelete(slp->slptr);
+				slp->slptr = NIL(Stak_t*);
+			}
 			free((void*)np->nvalue.ip);
 			np->nvalue.ip = 0;
 		}
diff --git a/src/cmd/ksh93/sh/parse.c b/src/cmd/ksh93/sh/parse.c
index 1f8dede51..744e5b55e 100644
--- a/src/cmd/ksh93/sh/parse.c
+++ b/src/cmd/ksh93/sh/parse.c
@@ -527,10 +527,16 @@ void sh_funstaks(register struct slnod *slp,int flag)
 		if(slp->slchild)
 			sh_funstaks(slp->slchild,flag);
 		slp = slp->slnext;
-		if(flag<=0)
-			stakdelete(slpold->slptr);
-		else
-			staklink(slpold->slptr);
+		if(slpold->slptr)
+		{
+			if(flag<=0)
+			{
+				stakdelete(slpold->slptr);
+				slpold->slptr = NIL(Stak_t*);
+			}
+			else
+				staklink(slpold->slptr);
+		}
 	}
 }
 /*
@@ -953,6 +959,7 @@ static Shnode_t *funct(Lex_t *lexp)
 		{
 			sh.st.staklist = slp->slnext;
 			stakdelete(slp->slptr);
+			slp->slptr = NIL(Stak_t*);
 		}
 		siglongjmp(*sh.jmplist,jmpval);
 	}
diff --git a/src/cmd/ksh93/sh/xec.c b/src/cmd/ksh93/sh/xec.c
index 45db4bed6..9d362241a 100644
--- a/src/cmd/ksh93/sh/xec.c
+++ b/src/cmd/ksh93/sh/xec.c
@@ -1421,7 +1421,8 @@ int sh_exec(register const Shnode_t *t, int flags)
 					/* increase refcnt for unset */
 					slp = (struct slnod*)np->nvenv;
 					sh_funstaks(slp->slchild,1);
-					staklink(slp->slptr);
+					if(slp->slptr)
+						staklink(slp->slptr);
 					if(nq)
 					{
 						Namval_t *mp=0;
@@ -1469,7 +1470,11 @@ int sh_exec(register const Shnode_t *t, int flags)
 					if(nq)
 						unset_instance(nq,&node,&nr,mode);
 					sh_funstaks(slp->slchild,-1);
-					stakdelete(slp->slptr);
+					if(slp->slptr)
+					{
+						stakdelete(slp->slptr);
+						slp->slptr = NIL(Stak_t*);
+					}
 					if(jmpval > SH_JMPFUN || (io && jmpval > SH_JMPIO))
 						siglongjmp(*sh.jmplist,jmpval);
 					goto setexit;
@@ -2485,7 +2490,11 @@ int sh_exec(register const Shnode_t *t, int flags)
 				struct Ufunction *rp = np->nvalue.rp;
 				slp = (struct slnod*)np->nvenv;
 				sh_funstaks(slp->slchild,-1);
-				stakdelete(slp->slptr);
+				if(slp->slptr)
+				{
+					stakdelete(slp->slptr);
+					slp->slptr = NIL(Stak_t*);
+				}
 				if(rp->sdict)
 				{
 					Namval_t *mp, *nq;
@@ -2521,7 +2530,8 @@ int sh_exec(register const Shnode_t *t, int flags)
 				struct comnod *ac = t->funct.functargs;
 				slp = t->funct.functstak;
 				sh_funstaks(slp->slchild,1);
-				staklink(slp->slptr);
+				if(slp->slptr)
+					staklink(slp->slptr);
 				np->nvenv = (char*)slp;
 				nv_funtree(np) = (int*)(t->funct.functtre);
 				np->nvalue.rp->hoffset = t->funct.functloc;
diff --git a/src/cmd/ksh93/tests/functions.sh b/src/cmd/ksh93/tests/functions.sh
index 1cffed0b3..a9e295627 100755
--- a/src/cmd/ksh93/tests/functions.sh
+++ b/src/cmd/ksh93/tests/functions.sh
@@ -1400,5 +1400,100 @@ else
 	unset exp
 fi
 
+# ======
+# funcname.ksh crashed
+# https://github.com/ksh93/ksh/issues/212
+cat >$tmp/funcname.ksh <<-'EOF'
+# tweaked version of funname.ksh by Daniel Douglas
+# https://gist.github.com/ormaaj/12874b68acd06ee98b59
+# Used by permission: "Consider all my gists MIT / do whatever."
+# https://github.com/ksh93/ksh/issues/212#issuecomment-807915937
+
+# run in subshell for additional regression testing
+(
+	IFS='-'  # element separator for "$*" etc., incl. "${FUNCNAME[*]}"
+	typeset -a FUNCNAME
+
+	function FUNCNAME.get {
+	    nameref self=${.sh.name}
+	    if (( .sh.subscript < .sh.level )); then
+		trap "(( .sh.level -= .sh.subscript + 1 )); eval '(( .sh.level = ${.sh.level} ))' \; _=\${.sh.fun}" DEBUG
+		trap - DEBUG;
+	    fi
+
+	    (( .sh.subscript < .sh.level - 2 )) && self[.sh.subscript + 1]=
+	}
+
+	function f {
+	    if (($1 < 10)); then
+		print -r -- "${FUNCNAME[*]}"
+		g $(($1 + 1))
+	    fi
+	    print -r -- "${FUNCNAME[*]}"
+	}
+
+	function g {
+	    if (($1 < 10)); then
+		print -r -- "${FUNCNAME[*]}"
+		f $(($1 + 1))
+	    fi
+	    print -r -- "${FUNCNAME[*]}"
+	}
+
+	#typeset -ft FUNCNAME.get f g
+	f 0
+)
+: do not optimize out the subshell
+EOF
+exp='f
+g-f
+f-g-f
+g-f-g-f
+f-g-f-g-f
+g-f-g-f-g-f
+f-g-f-g-f-g-f
+g-f-g-f-g-f-g-f
+f-g-f-g-f-g-f-g-f
+g-f-g-f-g-f-g-f-g-f
+f-g-f-g-f-g-f-g-f-g-f
+g-f-g-f-g-f-g-f-g-f-
+f-g-f-g-f-g-f-g-f--
+g-f-g-f-g-f-g-f---
+f-g-f-g-f-g-f----
+g-f-g-f-g-f-----
+f-g-f-g-f------
+g-f-g-f-------
+f-g-f--------
+g-f---------
+f----------'
+got=$(set +x; { "$SHELL" funcname.ksh ;} 2>&1)
+[[ $got == "$exp" ]] || err_exit 'funcname.ksh crash (direct run)' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+# dotting it slightly changes the output
+exp='f-
+g-f-
+f-g-f-
+g-f-g-f-
+f-g-f-g-f-
+g-f-g-f-g-f-
+f-g-f-g-f-g-f-
+g-f-g-f-g-f-g-f-
+f-g-f-g-f-g-f-g-f-
+g-f-g-f-g-f-g-f-g-f-
+f-g-f-g-f-g-f-g-f-g-f-
+g-f-g-f-g-f-g-f-g-f--
+f-g-f-g-f-g-f-g-f---
+g-f-g-f-g-f-g-f----
+f-g-f-g-f-g-f-----
+g-f-g-f-g-f------
+f-g-f-g-f-------
+g-f-g-f--------
+f-g-f---------
+g-f----------
+f-----------'
+got=$(set +x; { "$SHELL" -c '. ./funcname.ksh' ;} 2>&1)
+[[ $got == "$exp" ]] || err_exit 'funcname.ksh crash (dot)' \
+	"(expected $(printf %q "$exp"), got $(printf %q "$got"))"
+
 # ======
 exit $((Errors<125?Errors:125))