diff --git a/decode_test.go b/decode_test.go
index 72a8e465..0364b0bb 100644
--- a/decode_test.go
+++ b/decode_test.go
@@ -947,6 +947,7 @@ var unmarshalErrorTests = []struct {
 	{"%TAG !%79! tag:yaml.org,2002:\n---\nv: !%79!int '1'", "yaml: did not find expected whitespace"},
 	{"a:\n  1:\nb\n  2:", ".*could not find expected ':'"},
 	{"a: 1\nb: 2\nc 2\nd: 3\n", "^yaml: line 3: could not find expected ':'$"},
+	{"#\n-\n{", "yaml: line 3: could not find expected ':'"}, // Issue #665
 	{"0: [:!00 \xef", "yaml: incomplete UTF-8 octet sequence"}, // Issue #666
 	{
 		"a: &a [00,00,00,00,00,00,00,00,00]\n" +
diff --git a/parserc.go b/parserc.go
index ac66fccc..268558a0 100644
--- a/parserc.go
+++ b/parserc.go
@@ -687,6 +687,9 @@ func yaml_parser_parse_node(parser *yaml_parser_t, event *yaml_event_t, block, i
 func yaml_parser_parse_block_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
 	if first {
 		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
 		parser.marks = append(parser.marks, token.start_mark)
 		skip_token(parser)
 	}
@@ -786,7 +789,7 @@ func yaml_parser_split_stem_comment(parser *yaml_parser_t, stem_len int) {
 	}
 
 	token := peek_token(parser)
-	if token.typ != yaml_BLOCK_SEQUENCE_START_TOKEN && token.typ != yaml_BLOCK_MAPPING_START_TOKEN {
+	if token == nil || token.typ != yaml_BLOCK_SEQUENCE_START_TOKEN && token.typ != yaml_BLOCK_MAPPING_START_TOKEN {
 		return
 	}
 
@@ -813,6 +816,9 @@ func yaml_parser_split_stem_comment(parser *yaml_parser_t, stem_len int) {
 func yaml_parser_parse_block_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
 	if first {
 		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
 		parser.marks = append(parser.marks, token.start_mark)
 		skip_token(parser)
 	}
@@ -922,6 +928,9 @@ func yaml_parser_parse_block_mapping_value(parser *yaml_parser_t, event *yaml_ev
 func yaml_parser_parse_flow_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
 	if first {
 		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
 		parser.marks = append(parser.marks, token.start_mark)
 		skip_token(parser)
 	}