diff --git a/csst_ms_mbi_img_L1_fits.md b/csst_ms_mbi_img_L1_fits.md
index 0c1aa4131a07cb2bf22c37b902cc3ab771da8860..f4530d7ce04e017399ba2469498355fa7bebaf91 100644
--- a/csst_ms_mbi_img_L1_fits.md
+++ b/csst_ms_mbi_img_L1_fits.md
@@ -22,7 +22,7 @@
 |SATURATE   | 1833.333333333333         |                                                |                | f32  | csst_ms_mbi_instrument   |         
 |CRCOUNT    | 66791                     |                                                |                | i8   | csst_ms_mbi_instrument   |
 |INST_V     | '0.0.1   '                |                                                |                | str  | csst_ms_mbi_instrument   |
-|INST-TOL   | '2022-12-30T10:18:53'     | Time of last modification                      |                | str  | csst_ms_mbi_instrument   |
+|INST_TOL   | '2022-12-30T10:18:53'     | Time of last modification                      |                | str  | csst_ms_mbi_instrument   |
 |DATASUM    | '1352015684'              | data unit checksum updated 2022-10-28T19:29:10 |                | str  | csst_ms_mbi_instrument   |
 
 #### Header of `csst_ms_mbi_distortion`