diff --git a/tools/sm3.c b/tools/sm3.c
index 6b0ff118..380c01f3 100644
--- a/tools/sm3.c
+++ b/tools/sm3.c
@@ -35,8 +35,8 @@ static const char *help =
 "                           the default ID string '1234567812345678' is used\n"
 "    -in_str str            To be hashed string\n"
 "    -in file | stdin       To be hashed file path\n"
-"                           `-instr` and `-in` should not be used together\n"
-"                           If neither `-in` nor `-instr` specified, read from stdin\n"
+"                           `-in_str` and `-in` should not be used together\n"
+"                           If neither `-in` nor `-in_str` specified, read from stdin\n"
 "    -out file | stdout     Output file path. If not specified, output to stdout\n"
 "\n"
 "Examples\n"