diff --git a/lib/read.c b/lib/read.c
index 3fe08e1..d6d20ef 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -940,10 +940,12 @@ static int chain_to_list (hcl_t* hcl, hcl_cnode_t* obj, hcl_loc_t* loc)
 {
 	hcl_rstl_t* rstl;
 	int flagv;
+	int list_concode;
 
 	HCL_ASSERT (hcl, hcl->c->r.st != HCL_NULL);
 	rstl = hcl->c->r.st;
 	flagv = rstl->flagv;
+	list_concode = (hcl_concode_t)LIST_FLAG_GET_CONCODE(flagv);
 
 	if (flagv & CLOSED)
 	{
@@ -972,15 +974,13 @@ static int chain_to_list (hcl_t* hcl, hcl_cnode_t* obj, hcl_loc_t* loc)
 		if (HCL_CNODE_IS_CONS(obj) && HCL_CNODE_CONS_CONCODE(obj) != HCL_CONCODE_QLIST)
 		{
 			hcl_cnode_t* shell;
-
 			/* if the last element is another non-data list
-			 * for example, #( 1 2 . [ 3 4 5  ])
+			 * for example, #( 1 2 . #[ 3 4 5  ])
 			 * use a shell node to wrap the actual object list node head
 			 * for the compiler.
 			 */
 			shell = hcl_makecnodeshell(hcl, 0, HCL_CNODE_GET_LOC(obj), obj);
 			if (HCL_UNLIKELY(!shell)) return -1;
-
 			tail->u.cons.cdr = shell;
 		}
 		else
@@ -1022,6 +1022,14 @@ static int chain_to_list (hcl_t* hcl, hcl_cnode_t* obj, hcl_loc_t* loc)
 			fake_tok_ptr = &fake_tok;
 		}
 
+		if (list_concode == HCL_CONCODE_TUPLE && !HCL_CNODE_IS_SYMBOL_PLAIN(obj) && concode != HCL_CONCODE_TUPLE)
+		{
+			/* a tuple must contain some simple symbol names or nested tuples only  */
+/* TODO: filter out binop symbols */
+			hcl_setsynerrbfmt (hcl, HCL_SYNERR_VARNAME, HCL_CNODE_GET_LOC(obj), HCL_CNODE_GET_TOK(obj), "invalid name - not symbol in tuple");
+			return -1;
+		}
+
 		cons = hcl_makecnodecons(hcl, 0, (loc? loc: HCL_CNODE_GET_LOC(obj)), fake_tok_ptr, obj, HCL_NULL);
 		if (HCL_UNLIKELY(!cons)) return -1;
 
diff --git a/t/feed-5001.err b/t/feed-5001.err
index 89b00d2..cdcfdfd 100644
--- a/t/feed-5001.err
+++ b/t/feed-5001.err
@@ -52,7 +52,7 @@ a := #{
 	(printf "hello\n")
 );;
 
-k := [10 ; 20 ]; ##ERROR: syntax error - unexpected semicolon
+k := #[10 ; 20 ]; ##ERROR: syntax error - unexpected semicolon
 
 }
 
diff --git a/t/var-5001.err b/t/var-5001.err
index 7807475..b25746a 100644
--- a/t/var-5001.err
+++ b/t/var-5001.err
@@ -31,7 +31,7 @@ defun String length() { ##ERROR: syntax error - no argument list
 
 ---
 
-class A [ 10 ] { ##ERROR: syntax error - not variable name - 10
+class A [ 10 ] { ##ERROR: syntax error - invalid name - not symbol in tuple - 10
 }
 
 ---
@@ -47,7 +47,6 @@ class A [ [ [a] ] ] { ##ERROR: syntax error - not variable name
 class A [ a + ] { ##ERROR: syntax error - prohibited binary operator - +
 }
 
-## TODO: This check is supposed to fail. + must be treated as a binop symbol
-##---
-##class A [ + ] { ##   ERROR: syntax error - prohibited binary operator - +
-##}
+---
+class A [ + ] { ##ERROR: syntax error - prohibited binary operator - +
+}