diff --git a/cmd_parser.c b/cmd_parser.c
index 4cebc5c..cf66829 100644
--- a/cmd_parser.c
+++ b/cmd_parser.c
@@ -200,6 +200,7 @@ uint8_t atoi_byte(__xdata uint8_t *out, uint8_t idx)
 uint8_t atoi_short(__xdata uint16_t *vlan, uint8_t idx)
 {
 	uint8_t err = 1;
+	*vlan = 0;
 
 	while (isnumber(cmd_buffer[idx])) {
 		err = 0;
@@ -1190,6 +1191,7 @@ err:
 // Parse command into words
 // cmd_words_len contains the number of words found.
 // cmd_words_b[] contains only start of a word offset.
+// Returns the parsing status via `err_status`-variable.
 void cmd_tokenize(void) __banked
 {
 #ifdef DEBUG
diff --git a/cmd_parser.h b/cmd_parser.h
index dff8cf8..5e65c69 100644
--- a/cmd_parser.h
+++ b/cmd_parser.h
@@ -8,7 +8,7 @@
 extern __xdata uint8_t cmd_buffer[CMD_BUF_SIZE];
 extern __xdata uint8_t cmd_available;
 
-uint8_t cmd_tokenize(void) __banked;
+void cmd_tokenize(void) __banked;
 void cmd_parser(void) __banked;
 void execute_config(void) __banked;
 void print_sw_version(void) __banked;
diff --git a/rtlplayground.c b/rtlplayground.c
index 2d90077..9910785 100644
--- a/rtlplayground.c
+++ b/rtlplayground.c
@@ -26,6 +26,7 @@
 
 extern __code const struct machine machine;
 extern __xdata uint32_t flash_size;
+extern __xdata uint8_t err_status;
 
 extern __xdata uint16_t crc_value;
 __xdata struct machine_runtime machine_detected;
@@ -1307,7 +1308,8 @@ void idle(void)
 	// Check whether a command is waiting in the cmd_buffer and execute
 	if (cmd_available) {
 		cmd_available = 0;
-		if (!cmd_tokenize())
+		cmd_tokenize();
+		if (err_status == ERR_OK)
 			cmd_parser();
 		print_string("\n> ");
 	}