diff --git a/c/tex_parser/tex_table.c b/c/tex_parser/tex_table.c
index 74d0007..d74d613 100644
--- a/c/tex_parser/tex_table.c
+++ b/c/tex_parser/tex_table.c
@@ -76,6 +76,8 @@ int parse_table(const char *table_source, size_t len, struct table_s *table, str
 			} else if (c == '%') {
 				where_stack[++tex_level] = IN_COMMENT;
 
+			} else if (isgraph(c) || c < 0) {
+
 			} else {
 				error->code = (int)i;
 				error->message = "unexpected symbol (IN_UDEF)";
@@ -94,7 +96,8 @@ int parse_table(const char *table_source, size_t len, struct table_s *table, str
 			if (isalnum(c)) {
 				tag = zalloc_append8_str(tag, c);
 
-			} else if (!tag && (c == '\\' || c == ',' || c == '%')) {
+			} else if (!tag && (c == '\\' || c == ','
+			           || c == '%' || c == '_')) {
 				where_stack[tex_level--] = IN_UNDEF;
 
 			} else if (!tag) {