diff --git a/lib/comp.c b/lib/comp.c
index fcb3819..ccc5cdb 100644
--- a/lib/comp.c
+++ b/lib/comp.c
@@ -1429,7 +1429,12 @@ static int collect_vardcl_for_class (hcl_t* hcl, hcl_cnode_t* obj, hcl_cnode_t**
 
 		if (HCL_CNODE_IS_CONS_CONCODED(var, HCL_CONCODE_TUPLE)) /* [ ... ] */
 		{
-			if (enclosed) goto synerr_varname;
+			if (enclosed)
+			{
+			synerr_varname:
+				hcl_setsynerrbfmt (hcl, HCL_SYNERR_VARNAME, HCL_CNODE_GET_LOC(var), HCL_CNODE_GET_TOK(var), "not variable name");
+				return -1;
+			}
 			enclosed = 1;
 			dcl_saved = dcl;
 			dcl = var;
@@ -1442,12 +1447,9 @@ static int collect_vardcl_for_class (hcl_t* hcl, hcl_cnode_t* obj, hcl_cnode_t**
 			goto next;
 		}
 
-		if (!HCL_CNODE_IS_SYMBOL_PLAIN(var))
-		{
-		synerr_varname:
-			hcl_setsynerrbfmt (hcl, HCL_SYNERR_VARNAME, HCL_CNODE_GET_LOC(var), HCL_CNODE_GET_TOK(var), "not variable name");
-			return -1;
-		}
+		/* this check isn't needed as the reader guarantees this condition.
+		if (!HCL_CNODE_IS_SYMBOL_PLAIN(var) || HCL_CNODE_IS_SYMBOL_PLAIN_BINOP(var)) goto synerr_varname;*/
+		HCL_ASSERT (hcl, HCL_CNODE_IS_SYMBOL_PLAIN(var) && !HCL_CNODE_IS_SYMBOL_PLAIN_BINOP(var));
 
 		checkpoint = hcl->c->tv.s.len;
 		n = add_temporary_variable(hcl, HCL_CNODE_GET_TOK(var), tv_slen_saved);
diff --git a/lib/hcl-prv.h b/lib/hcl-prv.h
index 85b2e6f..af40bbb 100644
--- a/lib/hcl-prv.h
+++ b/lib/hcl-prv.h
@@ -416,6 +416,7 @@ typedef enum hcl_cnode_flag_t hcl_cnode_flag_t;
 
 #define HCL_CNODE_IS_SYMBOL(x) ((x)->cn_type == HCL_CNODE_SYMBOL)
 #define HCL_CNODE_IS_SYMBOL_PLAIN(x) ((x)->cn_type == HCL_CNODE_SYMBOL && (x)->u.symbol.syncode == 0)
+#define HCL_CNODE_IS_SYMBOL_PLAIN_BINOP(x) (HCL_CNODE_IS_SYMBOL_PLAIN(x) && hcl_is_binop_char((x)->cn_tok.ptr[0]))
 #define HCL_CNODE_IS_SYMBOL_SYNCODED(x, code) ((x)->cn_type == HCL_CNODE_SYMBOL && (x)->u.symbol.syncode == (code))
 #define HCL_CNODE_SYMBOL_SYNCODE(x) ((x)->u.symbol.syncode)
 
@@ -1962,6 +1963,11 @@ hcl_oow_t hcl_countcnodecons (hcl_t* hcl, hcl_cnode_t* cons);
 void hcl_dumpcnode (hcl_t* hcl,  hcl_cnode_t* c, int newline);
 
 
+/* ========================================================================= */
+/* read.c                                                                    */
+/* ========================================================================= */
+int hcl_is_binop_char (hcl_ooci_t c);
+
 /* ========================================================================= */
 /* exec.c                                                                    */
 /* ========================================================================= */
diff --git a/lib/read.c b/lib/read.c
index d6d20ef..d5c2c89 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -239,7 +239,7 @@ static HCL_INLINE int is_delimchar (hcl_ooci_t c)
 	       c == '#' || c == '\"' || c == '\'' || c == '\\' || is_spacechar(c) || c == HCL_OOCI_EOF;
 }
 
-static HCL_INLINE int is_binopchar (hcl_ooci_t c)
+int hcl_is_binop_char (hcl_ooci_t c)
 {
 	return c == '&' || c == '*' || c == '+' || c == '-' || c == '/' || c == '%' ||
 	       c == '<' || c == '>' || c == '=' || c == '@' || c == '|' || c == '~';
@@ -1022,10 +1022,10 @@ 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)
+		if (list_concode == HCL_CONCODE_TUPLE && concode != HCL_CONCODE_TUPLE &&
+		    (!HCL_CNODE_IS_SYMBOL_PLAIN(obj) || HCL_CNODE_IS_SYMBOL_PLAIN_BINOP(obj)))
 		{
 			/* 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;
 		}
@@ -2175,7 +2175,7 @@ static int flx_start (hcl_t* hcl, hcl_ooci_t c)
 			goto consumed;
 
 		default:
-			if (is_binopchar(c))
+			if (hcl_is_binop_char(c))
 			{
 				init_flx_binop (FLX_BINOP(hcl));
 				FEED_CONTINUE (hcl, HCL_FLX_BINOP);
@@ -2667,7 +2667,7 @@ static int flx_binop (hcl_t* hcl, hcl_ooci_t c) /* identifier */
 {
 	hcl_flx_binop_t* binop = FLX_BINOP(hcl);
 
-	if (is_binopchar(c))
+	if (hcl_is_binop_char(c))
 	{
 		ADD_TOKEN_CHAR (hcl, c);
 		goto consumed;
diff --git a/t/var-5001.err b/t/var-5001.err
index b25746a..3894798 100644
--- a/t/var-5001.err
+++ b/t/var-5001.err
@@ -48,5 +48,5 @@ class A [ a + ] { ##ERROR: syntax error - prohibited binary operator - +
 }
 
 ---
-class A [ + ] { ##ERROR: syntax error - prohibited binary operator - +
+class A [ + ] { ##ERROR: syntax error - invalid name - not symbol in tuple - +
 }